How assign original cheque number without maintaing cheque lot in FCHI

Dear Experts,

User maintains a payment method 'S' ( for example) for cheque payment in F110 and they don't want to maintain a dummy  cheque lots in FCHI.

So after the payment also ,there wont be any cheque information related to the that particular document in FB03.

They want to update the original cheque number when the payment acknowledgment receives from the bank.

So please guide me how to allocate this original cheque number eventhough it is not maintained in ECC.So that once payment acknowldegemnt comes..how can i Update the original bank cheque number to the payment document.

Note : Client will not purchase cheque lots from bank,

Please help.

Regards,

Tibin