cat flap installed into double glazed door

Greetings. I'm not holding out much hope in this one but here goes. We want to Install a cat flap through an existing double glazed door panel. We have enquired at couple of glazing shops but without success. We did this back in uk a while back and the glazier swapped out the glazed panel with a new one complete with factory fitted cat flap. Cost £100. Has anyone done this in spain? and if so, any advice?

Many thanks

Andy