In Excel2000, I have the following function:

Function WC_Name(ByVal WC)

WC_Name = Application.WorksheetFunction.VLookup(WC,
Workbooks("master.xls").Worksheets("fall06").Range ("b4:n500"), 13,
False)

End Function

The problem is that it does not work if the "master" file is not open.
How can I have the function open the file if it isn't already?

Thanks