Dynamic Image question

I finally got e-commerce set up for gift certificate sales and I'm looking to take it a set further. The default mail for a coupon purchase sends the token [coupon-number] to the user, which works fine if the coupon is only for use on the web. On our site I was asked to allow the user to use a coupon for a deposit for an event registration, but the coupon must be presented0 at the time of the event for the remaining balance...and here's my problem. I would like to send a gift certificate image to the user that includes the [coupon-number] values so that they can print out the coupon to give as a gift or bring to the event for registration. I have no experience in dynamic images and was hoping for some guidance if this is possible. Thanks in advance.

Justin