[Brentw]

Only 2 ways to do it.
Purchase a grill the has a separate regulator from the burner control. Then remove the reg and pipe in your lp connection hose.
Tee into your HP propane prior to your rigs regulator, use an extension hose such as a disposable connection hose. Note, when you disconnect this line there is a shyte ton of propane to depressure.

Okay, I'm a slow typist, great link in prior post.