COPA Exit 0002

Hi COPA Guru's

I have been working in COPA exit in order to convert a cost component into P Rate,

This change would be done only in one line item (Operating concern currency)

so i took the data from  ep_source

     ls_item-vvs05 = ( ls_item-vvs05 * (  P rate) ) .  [For Example]

         ep_target       = ls_item.

When i execute this my operating concern currency line item changed properly but Unfortunately my company code currency record also got changed for the same cost component which is not suppose to happen,

Can anyone help me understanding where im going wrong,

Thanks

Dhinesh