Copying of pricing procedure from billing to credit memo

Hi Gurus,

I have three pricing procedures, one is standard , one for power & one for credit/debit notes.

When i enter credit note against standard then accounting entery is rite bt when i issue credit note against power

then accounting entry is wrong as accounting key is erl in this case.

Kindly guide me solution so that i can enter credit notes for both standard procedure n power procedure as account keys n G/L is different for both procedures.

Thanks

Dushyant