Department code in Sage

Hi,

We are using department codes in Sage for different business areas.  We have the following scenario..

A customer will take multiple services from different business areas but will pay in one transaction.

What we want to do is to show the incoming cusotmer payment to the correct department code, otherwise when you run the departmental BS, the debtors figure shows no payments received.

It appears it can be done as when you look in Sage at a payment that has been split between different invoices there is a field for department code next to each split line, but I cannot figure it out!

Any help would be greatly appreciated.

Thanks