If you open anything.xls, you can use Edit|links to check.
If you're looking for a list of workbooks that use functions in your addin, then
there's nothing built into excel that allows you to know.
You could open each workbook that you own (on your harddrive, all your network
drives, all your CDs, all your DVDs, all your thumbdrives, all your floppy
drives....) and check, though.
Here's a routine that opens all the files in a specific folder to look for a
link to a specific workbook.
http://groups.google.co.uk/group/mi...e24ab?lnk=st&q=&rnum=1&hl=en#c9502712bf5e24ab
or
http://snipurl.com/wghm