Custom field in the attach serial plugin

Setting up to sell gift certificates via the coupon generator and attach serial. I now have everything working perfectly, client buys gift cert and Hikashop sends confirmation email with attached serial and gift cert.

Great.

Now I would like to be able to let the client nominate the gift cert for someone else. I assume I create a custom field as an item with the persons name as a text field and attach that to the gift certificate product. Then change the HI_CUSTOMER_SERIAL field in attach serial to whatever I call my custom field?

Say my custom field is.... GIFT_BENEFICIARY and the input would be the name of the person the gift cert is for, how do I get that into attach serial?
When I try it, where the persons name should be, I get gift_beneficiary. Obviously I'm doing something very wrong here but what?

That did it Jerome, thanks very much.
Regards,

Hello

Can someone tell me what is 'namekey', i do not find this label in the product table.

Actually i'm using a French version , i will tried to use the "code" fieldname with no success.
My product code is 'vol_00'

I also would like to display the order number, but i do not find how to do it.

This is attached below what i did so far.

Many thanks for your help,