How to get custom fields like Invoice number to show on Paypal receipts

How to get custom fields like Invoice number to show on Paypal receipts

We are using PayPal website payment pro and we can send money live and all
is well.
Our issues are:
when we view the recent payment, it should say "payment from John
Smith"...but ours just say "payment from". the name of the person does not
show up. well our accounting section wants it back. :-) not sure why its
not or which parameter of the DoDirectPayment request I need for this.
The user submission form has an invoice number field. I also need the
invoice number to show on the details page of the PayPal payment receipt.
I was able to get stuff like shipping address to show up by using its
parameter, but no idea to have Invoice Number show up.
I know it can be done because the old website had these and they used
website payments pro API to send payments. I just am not sure of how to do
this. thee is no mention of this in the API references that I see,
especially for DoDirectPayments method. Any help appreciated
Norman