how to change the display in standard program.."SAPLCKML_MR11_ALV"

hi....

one of the report of finance (SAPRCKMR11) is calling this program SAPLCKML_MR11_ALV ..for the display...

i had to add three more fields in the display...

1) PO quantity ekpo-menge

2) PO value ekpo-netwr

3) INCOTERM ekpo-inco1.

i had try to modify the standard program by copying it...but didnt getting the result.

please help me .... how to meet the requirement..... if u can tell please also tell me where in the program i have to do the changes...

any suggestion is appreciable..

thanks