Just put de generic box, then in the Specific tab you define your variable that way :
CP1:Test
CP2:MyValue
then you can reuse theses inside the Entry Prompts actions like this :
C:\Program Files\Avaya\IP Office\Voicemail Pro\VM\Wavs\$LOC\$CP1.WAV
You could also put the value of this variable inside a user-defined variable to use it with the Test User Variable box later....
As far I know, you can use $CP0 to $CP9. Each calls is a thread so you can assign different values to theses variable and it will be attach to the current call. Once the call get out of the voicemail the variable content is cleared...
I use them a lot...more than user variable.