The function to use is SetWindowText(). Here is an example:

          case DLG_INIT:
                    // get the dialog’s window handle

                    hwndDlg = CmdGetHwndDlg (szDialogName);

                    // set the custom dialog box window title

                    SetWindowText (hwndDlg, “Select Options”);

You first must call CmdGetHwndDlg() to get the handle to the dialog box. Then, just call SetWindowText() with the dialog handle and the title.

That’s it!