Card reader. i have a memory card reader, model unknown, from another pc branded INFINITY. i would

Question

i have a memory card reader, model unknown, from another pc branded INFINITY. i would like to fit it to my SYSTEMAX, which is approx 6/7 years old. the mc reader is about 4 years old. at the moment, i have a floppy disc drive, which i would like to remove, to fit the mc reader, or leave functioning, also. i cannot find any plug internal or external which matches the reader. OR MAYBE DONT KNOW WHERE TO LOOK! i would much appreciate your expert help. thank you very much, V. Guerra, Essex, uk.