The two user variables created in each project will pull the ID and the name of the learner. If the employee has a similar account that should be possible as well. But I don't know what you mean exactly.
The LMS may not necessarily be using the same ID for the student as the company's HR software system uses as their employee ID. You would need to check. But in any case, Captivate's user variables are only grabbing the data that is provided by the LMS to identify the student when they log on.