You can, you set it by Tools>Share Workbook....
But shared workbooks are not a good idea, Excel was not designed to be
multi-access, and some of the functions are restricted. I personally
wouldn't touch them.

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HTH
Bob
(there's no email, no snail mail, but somewhere should be gmail in my addy)
>I was wondering if anyone knows if you can have a file on a server and be
> able to open it in two different locations. I have a file that I need two
> people to work on but at two different locations and would like it if it
> would automatically update so that both people would see the revisions. I
> don't know if this is even possible