Regardig Pricing routine for ME21N

Experts,

my requirement is to automatically update/set

KOMV-KPEIN(Amount-unit value) field with KOMV-KAWRT(cond. base value)

value for a particular condition type 'ZF03'.

for this i created a Pricing routine in VOFM Tcode for application 'EF'.

problem is:

when i manually give amount value at header section in me21n the program works and updates the unit value with condition base value for ZF03 condition type.

but if i change PO quantity at item level for any material which updates KOMV-KAWRT value in background with new value, at that time My routine is not working and not further updating KOMV-KPEIN from newly updated KOMV-KAWRT

even tough the breakpoint is triggering , KOMV-KAWRT value comes as old one only in above case.

I think after processing of my routine The main Table KOMV gets updated,

and this is correct also as i debugged i found after processing of my routine Form > XKOMV_LESEN triggers which updates KOMV with new values .

now what should i do so that my requirement gets fulfilled in each case,