Conditional search for text substrings

Hello,

This is one of several nested conditional statements that if I can get to work as required I can modify the remaining statements:

=IF((VLOOKUP(A2,'Second Worksheet'!A$2:M$100,7,FALSE) = "*TRACTOR*"),(C2+10000),"")

My troubleshooting has reduced the apparent problem to trying to make this conditional statement example work as required:

=IF((G10="*TRACTOR*"),(C2+10000),"")

It is not treating the asteriks as wildcards. The field G10 might have any of the followng values: Tractor, Truck Tractor, HET Tractor, Tractor Truck, as well as Crane, Van, Minivan, Forklift, etc. I want to test for any occurence withind the cell or as in the first actual case the value returned from a cell via a VLOOKUP search of a specific text substring.

I am creating the workbook use with Excel 2003.

TIA