Anyone in the TA can do this regardless of what unit you are from.
On Tuesday just go in and see your PSI, tell him that you're tired of being in a sh!tty hat regiment and you want to be Airborne so that you can impress his wife/daughter and get her to suck you off at the next Regimental get together.
There just aren't enough of these P Coy threads. I'd hate to wear wings on my uniform. I'd be mortified if people though I dressed up as a lass at the weekend and sucked off all my mates when I was drunk.