PAYE Credits and Refund

I am new to Quickfile, and I’m migrating my records for this year (Nov13-Oct14), into Quickfile.
I’m trying to understand purchase credits. I have credits for PAYE and NI, in respect of my only employee who has been on maternity leave, previous & this year.
Those credits exceed the PAYE liabilities I have for this year. I have allocated last year’s credits to an opening journal against the nominal acc ‘PAYE’. So how do I record this year’s credits, and liabilities, and then allocate them all against a refund cheque from HMRC.