Generic logins

Hi, i am hoping for some help. My company uses a generic login for windows start up, and then we have individual logind for the sperate programs that we run.
i am wanting to create a shared workbook in Excel for my department, but because of the generic login for the windows start up, when ever anyone opens up the workbook from their station it uses the generic login for tracking changes, and inserting comments... i know how to change the user name in the genreal tab in the options menu, but is there a way to have a prompt open up , when the work book opens that ask the user to insert there name??

any help would be greatly apprecitated...
thanks So Much
Moni

http://www.ozgrid.com/forum/showthread.php?t=32869
shows an example of spread sheet with user/password log in