Remaining amount in forward contract

Dear Experts,

How to identify the remaining amount in the original contract after making premature settlement?

For example:

We have USD 10000 in original contract. We have done a premature settlement for USD 2000. The system should display the remaining amount while making subsequent premature settlement. How this can be achieved? This seems to be very basic requirement but the system does not seem to have any option in this regard.

Thanks,

Vinod P