RMA for certain lines only

Hi,

We have put the constraint of not adding new lines to the Booked Order.

Now we want to create an RMA order, for few lines of the Booked Order or few quantities of the booked order.

How can this be achieved.

For eg:

We have Booked an Order 1234 of 10 Lines each asking for 5 quantities of a particular item.

Now we want to Return only 3 lines with quantities less than 5.

Please suggest possible solution.

Regards,

Gulnar