Comaddins

what is the commaddins used for?? can it be used to send commands to windows???

A COMAdd-In is basically an Add-In for whatever Office program it was written for.

For ex. if I wanted to write an addin to make a backup copy of my Outlook pst file I would use vb to write
the program to add a new menu item to execute my program. My program would make the backup copy
when the menu was clicked on.

Now this program would be integrated with outlook using IDExtensibility2 procedures, etc.