If you create the variable(s) in Captivate, Captivate will attempt to save the values in the suspend data. It depends on your LMS if the data is saved and if you can run a report against that data.
The suspend data from Captivate is not quite human-readable, it is not saved as easily read name:value or name=value pairs. What I normally do is to wrap the value in easily searched strings: myVar="zzz8zzz". Then I can search for the first and second instance of zzz and the value I want is in between.