customs declaration registration

Dears all,

i need to register some Customs Declarations form on SAP B1.

On my old ERP I used to register it like an invoice with counterpart the customs.

i.e.: DHL Customs credit 120

VAT debit 20

DHL Customs debit 100

then, i receive the invoice from DHL for their commission and i register a new invoice like that:

DHL credit 30

DHL Customs debit 20 (for VAT advance payment)

administrative cost debit 10

So the Supplier DHL Customs total at 0 and I have all in order.

The problem in SAP B1 is that when i register an invoice, i can't choose a patrimonial G/L account but only Cost or revenues.

Could you give me an help to how to register it?

Thanks