Pricing Proc being copied from inv to cred mem req but I want as per determ

Hi All,

I have made an oder, then delivered and made an invoice.

I have changed pricing procedure detremination such that invoice pricing will be "INVOICE" and in Credit memo it will be "CREDIT" with the help of document pricing procedure key every thig else remins the same.

now when I make Credit meo request wit href to Sales order new pricing procedure is determined as "CREDIT" but when create with Reference to Invoice the pricing procedure comes as "INVOICE"

my requirement is when i make credit memo request from invoice "CREDIT" should come as pricing procedure.

I tried various copy control settings in routines. please advise how it could be done.

please advise.