|I assume you have a table someplace that has the percentage that is associated with each client.|
If so, use a VLOOKUP function in Column C to return the percentage associated with each client.
e.g. =VLOOKUP(B1, SHEET2!$A$1:$B$10, 2, 0)
Read up on the VLOOKUP function in the Excel Help files.
If you need some help getting it to work, come on back. You'll probably have to supply a little more detail if you want us to actually construct the formula for you.
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