Connecting Vari 300 crate to ex pen?!

[Raven bauer]

Hi,
I have a Vari 300 crate that is currently inside the expen, as I used double sided snaps to connect the metal vents to the ex pen.
Problem: came home over lunch today and the 8 week old puppy must have gotten out of the pen by somehow getting on top of the crate and the over the ex pen.

So, I need to move the crate out of the pen and just connect the front part, around the opening of the crate to the ex pen. The question is how? The metal vents are a bit far back and he will squeeze through small gaps between ex pen and crate.

Am I making sense? I am hoping to avoid to get a wire crate.

Thanks!!