You can go to Lowe's and get a 1" hosebarb and shove it in your LP opening. When I had those bags I did that and then taped and hoseclamped it together. It's a more permanent connection as you may not be able to put the end caps back in after doing this, but it is a very solid connection. The fittings can be found in the water irrigation systems area (not garden hose area) and are Sch. 40 PVC. You can pretty much mix and match those fittings to get to anything you need.
Ohh wait...I have pictures!