Allow Option to Modify Check Voucher. Need Additional Columns from Bill

Allow Option to Modify Check Voucher. Need Additional Columns from Bill

We really want to add a custom field/value from a Bill to the check Voucher. Is this possible? If not, why is there such a restriction? We are having an admin hand write information on all the vouchers, even though the information already exists on the Bill being paid by the check. This would save us hours of work each week if we could display a value from a field on the corresponding Bill. Please advise.