I have 2 cameras for which I was never able to solve this - a quick release-type holder for hand mic (in this case Shure SM58, although the brand is more or less irrelevant) for ENG type work - eg: reporter is handed the mic with associated cube transmitter for quick interviews.
In my experience, I'm looking for a piece of hardware that bolts to the camera body, and ends in a 5/8" male thread, to which the manufacturer-specific quick-release yoke can be threaded.
Panasonic Pro Parts sends me to B&H, which tries to help with boom mic-type accessories (ie : no understanding of the application). I assume someone else with these ENG cameras must have come up against this and solved it?
The 2 cameras in question are the HPX-500P and HPX-2000P, and they appear to have very similar 'hard points' for this. (the cameras ship without any bolts inserted).
I once (mid 90's??) purchased a beautifully machined version (out of stainless) for use on XD-Cam, still in service; I think the company was Stalionis Eng. out of Baltimore, but I've not been able to find any trace of the company. (I'm imagining a retired video pro with lathe skills and a sense of pride).