HML Checker

Add "Save Project File As" to the file menu and the Ctrl+Shift+S shortcut. Associate the controls with the system default save file dialog.

Then implement code to write to the file, for CSV/TXT obviously save all as text with either comma or tab (\t) as the separating character, but for XLSX try to save the column cell type associated with the column and possibly any formatting that was originally associated with the worksheet if it was opened.

Note: For new unsaved Excel worksheets, bolden and freeze the top row on the saved worksheet.