You can't program a other keyfob to a existing skreem module. If you have at least one working key (the remote part) it is possible to make a new one with this key, if not it is possible but not so easy, the processor from the skreem has to be desoldered, read out and resoldered.
A cheap solution for you were my
Skreemulator Test Kit Rudy will program your ECU so that it works with the Skreemulator. Then you don't need a original Crossfire Key any more. Of course you need a keyblade for the ignigion switch and the door lock but the included RF Systems has a remote controll to open/close the car and deactivates the immobilizer over my Skreemulator.
If you been
unsettle because of the beta status, I haven't heard of any problems from the existing beta testers and you can also wait for the final version. But this takes almost one or two month to be ready.