How deeply do you wish to learn?
For your work pass if you have cloned it with a keysy then you are probably good to go as the keysy cards are based on the t5577 which is the most common low frequency chip in Dangerous things products. It can pretend to be a lot of different low frequency chips.
If your work access system is based on an Em4x chip (it might be) then you can enroll your work card in your XAC access controller.
If not then if you really want to learn things you could implement an access controller using an off the shelf reader module and an Arduino micro controller.
You might want to check out the improved keyboard wedge thread for an NFC reader that can be used to input your password into a computer.
A different Arduino, and a bit of finagling and you should be able to build an access controller.