Sorry. Having a blonde moment. Will the target file be OPEN or CLOSED? If CLOSED, you're in trouble, unless you can use 3rd party software. INDIRECT.EXT is what you need. It is no longer supported but can work perfectly well with 2010. I am not 100% certain that it works reliably over a network. All users must have it installed, too.

Google indirect.ext Excel 2010 for free download & instructions.

If this is a non-runner, you're stuck.