I need a formula to deal with the following problem.

If ORDERS are 4 or more AND MONTHLY CUMULATIVE is greater than or equal
to 750000 then everything up to 749999 is at .075% bonus and everything
greater than or equal to 750000 is at .01% bonus. If ORDERS are less
than 4 then no bonus. If amount less then 750000 but orders are 4 or
more then bonus is at .075%.

I have tried
=IF(AND(E4=$B$14,G4=$B$20),((G4-$B$20)*$B$17)+(F4-(G4-$B$20))*($B$16),IF(E4<B14,0,F4*$B$16))
in cell H4 but this fails


E2 F2 G2
H2
Orders Invoice_Value May_Cum Commission
4 150000 850000 ?


Thanks in anticipation


John