You should just be able define your data range regardless of whether it's in
the same workbook or not.  You can have multiple sets of data be drawn into
one chart, from several workbooks.  First, open up the workbooks you want to
draw data from (in addition to the one where you will have the graph).  Start
the Graph wizard in your "Master" workbook.  When you get to the second step
of the Graph Wizard, click on the colored icon at the right of the Data Range
field and select your data ranges from the other workbooks.  The rest should
be fairly simple.

Eddie O