Match list of attending staff to list of all staff

I'm going to be honest and say I have little to idea what I'm doing, so please keep it simple if possible.

I have a security software that gives me a report of who came in on any given day. HQ would like to know how many staff are coming in on a given day (easy) and how often individual staff are attending. 

I need "security report" to magically turn into "attendance records" per this example.

Any help greatly appreciated.