diff --git a/crates/ui-egui/src/control.rs b/crates/ui-egui/src/control.rs
index 2ea5cfae0..344284598 100644
--- a/crates/ui-egui/src/control.rs
+++ b/crates/ui-egui/src/control.rs
@@ -252,7 +252,7 @@ pub fn handle(app: &mut SheetApp, ctx: &egui::Context, method: &str, p: &Json) -
         "ui.dialog.confirm" => match app.dialog.take() {
             Some(d) => match d.command {
                 Some(cmd) => {
-                    let params = Json::Object(d.values.clone());
+                    let params = crate::dialogs::build_params(&d);
                     let r = app.run(cmd, params);
                     if r.is_err() {
                         app.dialog = Some(d);
diff --git a/crates/ui-egui/src/dialogs.rs b/crates/ui-egui/src/dialogs.rs
index ada19d3a4..d241e540d 100644
--- a/crates/ui-egui/src/dialogs.rs
+++ b/crates/ui-egui/src/dialogs.rs
@@ -957,7 +957,8 @@ fn data_validation_form(ui: &mut egui::Ui, d: &mut Dialog, confirm: &mut bool, o
 }
 
 /// Builds the command params from form values for dialogs that need translation.
-fn build_params(d: &Dialog) -> Json {
+/// The parameters OK sends to the dialog's command: its field values, reshaped per dialog.
+pub(crate) fn build_params(d: &Dialog) -> Json {
     let mut v = Json::Object(d.values.clone());
     match d.name.as_str() {
         "dataValidation" => {
diff --git a/crates/ui-egui/tests/dialog_confirm.rs b/crates/ui-egui/tests/dialog_confirm.rs
new file mode 100644
index 000000000..8ec98b040
--- /dev/null
+++ b/crates/ui-egui/tests/dialog_confirm.rs
@@ -0,0 +1,60 @@
+//! `ui.dialog.confirm` runs a dialog's command with the parameters its OK button sends (#1459).
+
+use egui::vec2;
+use gridcraft_engine::Session;
+use gridcraft_engine::model::CfRule;
+use gridcraft_ui_egui::SheetApp;
+use gridcraft_ui_egui::control::{Outcome, handle};
+use serde_json::{Value as Json, json};
+
+fn harness() -> egui_kittest::Harness<'static, SheetApp> {
+    let mut session = Session::new();
+    session.new_workbook();
+    let mut h = egui_kittest::Harness::builder().with_size(vec2(1200.0, 800.0)).build_ui_state(
+        |ui, app: &mut SheetApp| {
+            app.logic(&ui.ctx().clone());
+            app.ui(ui);
+        },
+        SheetApp::new(session, Default::default()),
+    );
+    h.run_steps(6);
+    h
+}
+
+fn control(h: &mut egui_kittest::Harness<'static, SheetApp>, method: &str, params: Json) -> Json {
+    let ctx = h.ctx.clone();
+    match handle(h.state_mut(), &ctx, method, &params) {
+        Outcome::Done(v) => v,
+        Outcome::Screenshot { .. } => json!(null),
+    }
+}
+
+#[test]
+fn confirming_a_highlight_cells_rule_adds_the_rule_like_ok() {
+    let mut h = harness();
+    h.state_mut().run("range.setValues", json!({"range": "A1", "values": [[1], [3]]})).unwrap();
+    h.state_mut().run("selection.set", json!({"range": "A1:A2"})).unwrap();
+    // Home › Conditional Formatting › Highlight Cells Rules › Greater Than…
+    control(&mut h, "ui.dialog", json!({"name": "cfQuick", "type": "cellIs", "operator": "greaterThan", "title": "Greater Than"}));
+    control(&mut h, "ui.dialog.set", json!({"field": "value", "value": "2"}));
+    let r = control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(r["ok"], json!(true), "{r}");
+    assert!(h.state().dialog.is_none(), "the dialog closed");
+    let sheet = h.state().session.active().unwrap().wb.active().unwrap();
+    assert_eq!(sheet.cond_formats.len(), 1, "{:?}", sheet.cond_formats);
+    let rule = &sheet.cond_formats[0].rule;
+    assert!(matches!(rule, CfRule::CellIs { a, .. } if a == "2"), "{rule:?}");
+}
+
+#[test]
+fn confirming_text_to_columns_splits_on_the_ticked_delimiter() {
+    let mut h = harness();
+    h.state_mut().run("range.setValues", json!({"range": "A1", "values": [["a;b"], ["c;d"]]})).unwrap();
+    h.state_mut().run("selection.set", json!({"range": "A1:A2"})).unwrap();
+    control(&mut h, "ui.dialog", json!({"name": "textToColumns"}));
+    control(&mut h, "ui.dialog.set", json!({"field": "semicolon", "value": true}));
+    let r = control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(r["ok"], json!(true), "{r}");
+    let read = h.state_mut().run("sheet.read", json!({"range": "A1:B2"})).unwrap();
+    assert_eq!(read["values"], json!([["a", "b"], ["c", "d"]]), "{read}");
+}
diff --git a/docs/control-protocol.md b/docs/control-protocol.md
index e82ae7299..3979b51fd 100644
--- a/docs/control-protocol.md
+++ b/docs/control-protocol.md
@@ -35,7 +35,7 @@ connection; nothing sent after it runs. Blank lines are skipped.
 | `ui.key` / `ui.text` | `{key, shift?, cmd?, alt?, ctrl?}` / `{text}` | Keyboard input (typing in the grid starts editing) |
 | `ui.edit.begin` / `ui.edit.text` / `ui.edit.commit` / `ui.edit.cancel` | `{text?}` / `{move?: down\|right\|up\|left\|none}` | Drive the cell editor |
 | `ui.ribbon` | `{tab}` | Switch ribbon tab |
-| `ui.dialog` / `ui.dialog.set` / `ui.dialog.confirm` / `ui.dialog.cancel` | `{name}` / `{field, value}` | Open, fill in and confirm dialogs |
+| `ui.dialog` / `ui.dialog.set` / `ui.dialog.confirm` / `ui.dialog.cancel` | `{name}` / `{field, value}` | Open, fill in and confirm dialogs; `confirm` runs the dialog's command with the same parameters as its OK button |
 | `ui.backstage` (via `engine.execute`) | `{page?: home\|new\|open\|info\|saveAs\|print\|export\|options\|close}` | Open the File tab's Backstage view on a page, or close it (`ui.inspect` reports the open page as `backstage`) |
 | `ui.screenshot` | `{path?}` | PNG of the window (base64 when no path). Animations are settled first: the picture shows the final state |
 | `ui.set` | `{dark?, formulaBar?, ribbonCollapsed?, animations?}` | UI preferences (`formulaBar` runs `view.formulaBar`) |