How to Search For a URL in a Large Number of Excel Files?

I would like to find a way to search all the Excel Files in a hard
disk to look for a specific URL. We are in the process of moving a
shared network folder from one server to another server (such as from \
\FileSrv1\IS_Dept to \\FileSrv2\IS_Dept). Unfortunately, many people
have embedded the URL of the shared network folder in Excel and Words
documents. I am afraid that after the move, those links will not
work. Therefore, I am looking for a way to identify those files that
have embedded that specific URL; then I can ask the users to change
the URL after the move.

I have tried using Windows Search function (in My-Computer) and the
FIND command in command prompt. None work.

Please help. Thanks.

Jay Chan