Question : Graduated Commission Scale

Here's a challenge,

I have a table of sales reps, (name and ID)
I have a table of sales reps graduated commission levels (ID, Level, Rate) -
ie.
Jane Smith, $0, 1%
Jane Smith, $100,000, 2%;
Jane Smith, $250,000, 3%;
Jane Smith, $500,000, 5%

I have a table of sales transactions.

The query I'm trying to create is to calculate the sales rep commission for the month.  If Jane Smith sells $350,000 for the month, the first $100,000 @ 1% is $1,000 plus the next $150,000 is @ 2% for $3,000 plus the last $100,000 is @ 3% for $3,000 for total commisions of $7,000 for the month

I am pretty sure I can solve this with VBA, but I'd rather a query solution if anyone out there has any ideas.

Thanks!

Answer : Graduated Commission Scale

Actually, if you sort the commission levels as highest dollar limit (and percentage) to lowest you could get away with the following logic for the loop:

with rst_commission_structure
Do Until .eof

 if rst_commission_structure![level] > SalesLevel then
   Commission = Commission _
   + (SalesLevel - rst_commission_structure![level]) _
      * rst_commission_structure![rate]
   SalesLevel = rst_commission_structure![level]
 endif

 .movenext
Loop
end with