PO# field in AR Aging Report(s)

Hi Experts,

We have a requirement to bring PO# in AR Aging Report(s). We have used "reference" field from FBL5N as of now but it's a free field, and it brings invoice number, Customer PO number etc.

Requirement is to bring PO numbers only in AR Aging reports. so Is there any other field which we can use in AR Reports to fulfill this requirement? and How?

Please suggest!!!!

Thanks,

Bhavin Vyas