Updation of book value at ineterest accrual

Hi Experts,

We have configured a commercial paper product for our client.However, the client does not use the amortisation run i.e TPM1 for amortisation but instead uses TPM44 i.e accrual run where he debits the "Investment in Commercial paper A/C" . Accordingly, even though the Investment A/C value goes up at each accrual run, the Book value remains the same.

Please could you suggest any method where you can update the Book Value column at Accrual runs.

Regards,

Sonal