There are "high pressure" and "low pressure" propane appliances.
Things like BBQs and outdoor stoves are often "high pressure". The working pressure is usually around 10-20 p.s.i.
RV type appliances are typically "low pressure". The working pressure is around 1/2 p.s.i.
That's the pressure at the part of the appliance that is doing the work (the burner), NOT the pressure in the supply tank. Supply tank pressure can be thought of as "even higher pressure". A 5 gallon tank might be up around 120 p.s.i. Even the little 1 lb. disposable bottles can be up around 100 p.s.i.
So...you gotta have a regulator to control the pressure. In a typical RV setup, there is a central regulator which hooks to the tank, and all the plumbing after that is only carrying the 1/2 p.s.i. low pressure.
If the appliance was designed to hook up directly to a propane tank (either big refillable or a little disposable), then it has to have a built-in regulator.
So check your stove out. It almost certainly has a built-in regulator. If it does, and the only thing you are using the propane tank for is that stove, then you can just change out the hose for one that has an ACME connector for the 5 gallon tank on the end instead of the hose you have now that has a connector for the disposable bottles.
Mr. Heater sells hoses like that to connect their Buddy heaters to a 5 gallon tank:
http://www.mrheater.com/productdetails.aspx?catid=355&id=355