Regarding Text in Credit note

Dear All,

I have taken 5 Materials from Customers ( Returns ) and raised Retruns sales order / Delivery and Credit Memo.

In my credit note i have to get the text as " Credit note towards customer returns order number XXXXXXX "

i.e. on the print of the Credit note i have to get as above how to do this.

Can any one help on this ?

Siva