Closing Excel or Word doc in Webviewer

Hello,

I am hoping that someone has an idea of what I could do to circumvent this problem:

I open a document (excel or word) in the webviewer. If during the same session I want to delete the file, it tells me that the file is locked or in use (even if I am no longer looking at the file, the webviewer has been refreshed with another file or it is blank).

If I check in task manager, it shows me that excel is running (it's not in my taskbar). It looks like the file stays "in use" even if I exit FileMaker: the only way I found to unlock the file was to log off or end the Excel process in task manager...

I thought that I should write a routine that "flags" files to be deleted, make them invisible to the users, and run this routine in a batch at night...

Or is there some script step that I missed that would either close the excel process or simply the file while in FileMaker?

Thanks for any pointers, MF

Note: I delete the file using a tip from FM Advisor where you omit all records and export a null record to the filename to be deleted.