That's a good link LJAZ provided. As long as you can remove the regulator and still have a burner control (a lot of portable grills have the burner control as part of the regulator) it can be adapted to run off the trailer's quick connect.
Here's a picture of my modified Weber Q120 with Quick Connect system installed in place of the regulator:
You can get multiple hoses for the system in various lengths; I have a 4', 2x12' and even a 20'. I've converted my Campfire-in-a-Can to run off the system, too and I have all the multiple hoses to allow placement of the campfire in a position that is convenient:
One more point, keep the regulator...I discovered once, that I had a need, or rather, a desire to take our grill away from the trailer for an "offsite" picnic. Drat, I'd converted the grill!!! I had an "aha" moment and being the packrat that I am, I'd kept the regulators from a bunch of equipment (they are actually all the same; propane devices are built around a regulated pressure of about 11 psi). I modified a couple of the regulators to attach to 1 lb cans and 20 lb tanks to be "Quick Connect":
I carry these with me now and when I want to, I can quick connect the regulator back onto the device and use the tank(s) for LP when not near the trailer; if I want an offsite picnic, I put the 1 lb bottle connector back on, if I want a campfire at another site, I can put the 20 lb. connector on or even, using a hose between the grill and the regulator (remember, they are quick connect now) use a 20 lb tank, something the original Weber was never designed for...
There are many connectors out there that look alike, but, there are differences and they aren't interchangeable. The low pressure connectors are of the Sturgis 250 variety. There are air connectors, high pressure LP connectors, natural gas high and low, and while they, at first blush, all look alike, there are minute changes in measurements designed to prevent the wrong valve from being able to connect to a non-mating connector. Sometimes just a few thousandths of an inch difference, but, they won't mate (don't ask how I discovered this...). Another source of supplies is:
Good luck with your mod!