SD Pricing

hei all,

please help.

i have these requirement regarding SD pricing.

i have 3 condition type.

cond type ZZCA --> calc type : Fixed amount.

cond type ZZCB --> calc type : fixed amount

cond type ZZZZ --> calc type : quantity

let say: value of cond type ZZCA = 100, then ZZCB 25.

then i want condition rate of ZZZZ (KBETR) will be (ZZCA/ZZCB) --> 100/25 = 4

so, when i made sales order with quantity = 50 PCS, and ZZCA = 100, ZZCB = 25, the value of ZZZZ will be

=(100/25) * 50 PCS

=100$

how we do that? do we have to use routine in VOFM or user exit?

can anyone give me the code for this requirement.

you valuable input will be highly appreciated.

Best Regard,

Hendry