Figuring resistor wattage and value
I'm going to take a WAG and assume this LED you have is designed for automotive use on a "12VDC" source (typically more like 14V), so it already has a resistor in there. Be sure to verify this before hooking it up to a supply directly or you could damage the LED!  

In that case, you will only need to add to the resistor(s) that are in there. 

You can attach it to a power supply that outputs something like 14V (preferably a bench supply) and measure the current Im. Take that current Im, let's say it's 100mA, and calculate the value of the extra resistor: 

Rs = \$\frac{22V-14V}{Im}\$   so for our example, it would be 80 ohms. 

Pick a standard E24 value that's the same or a bit higher (say 82 Ohms in this case). 

Power will be \$\frac{(22V-14V)^2}{R}\$, so for our example 0.8W. Pick one that's a bit higher, say 1W or 2W. 

Go to your favorite distributor and find a resistor with the required specs.