You can assign a macro to its onaction property or replace the button. You
can't override a method of the Workbook in VBA in anyway I can think of.

http://support.microsoft.com/default...b;en-us;830502
How to customize menus and menu bars in Excel

http://support.microsoft.com/default...b;en-us;166755
File Title: Customizing Menu Bars, Menus, and Menu Items in Microsoft(R)
Excel 97
File Name: WE1183.EXE
File Size: 58041 bytes
File Date: 06/20/97
Keywords: kbfile kbappnote
Description: This Application Note can help you learn techniques for writing
Visual Basic(R) for Applications code to customize menus in Microsoft Excel
97. This Application Note contains code examples that you can use with the
following elements: menu bars, menus, menu items, submenus, and shortcut
menus.

--
Regards,
Tom Ogilvy


"Priya" wrote in message
...
Hi,

I need to capture the "Send this sheet" button click event to override its
functionality. "Send this Sheet" can be found on opening File - Send
To -
Mail Recepient.

It can also be found using ActiveWorkbook.EnvelopeVisible = True in VBA.

Thanks!