It should be possible to create Employees records via SuiteScript so you could:
• Do a CSV import to get all your current employees from System A to System B.
• If you want the new employees created in System A to also be created in System B automatically then you are going to need that integration which could be something like:
• UserEvent script deployed to the Employee record on System A that on create send the Employee data to System B (via a RESTlet on System B) that would handle the Employee creation on System B.
This is just an idea, if you don’t need that to happen in real time then it could very well be an scheduled Map Reduce on System A that periodically sends newly created employees data to System B (RESTlet).