Common FI Document for different Payment Method in F110

The scenario is-

Down Payment of Rs. 10000 has done to a Vendor with reference to Special GL Indicator.

Subsequently, 10 nos of Invoice Verification has done in the Vendor a/c with Rs. 10000 each.

So credit balance of Rs, 90000 (100000-10000) is lying in Vendor a/c.

When we are making payment through F110 then the down payment line item required payment menthod which belongs to incoming payment.

I have created separaate payment method for incoming payment and assigned it to line item of down payment but system is genrating separate document for down payment line item and other normal 10 line item.

How we can generate a common document for Rs. 90000/- after clearing the down payment line item with normal line item.

Regards,