How to pass variable between different variable
 

Dear all,
I have browse this newsgroup and I found that it is
possible to pass variable between two workbooks. I can referenced to
another workbook in VB editor. But the problem is that both workbook
needed to be opened. Can I reference to variable of other workbook that
is not opened in excel?
For example, I open workbook A and Workbook B is closed, then I
reference from workbook A to workbook b's Variable with Workbook B is
not opened.

Thanks