Internal/External audio idea? would it work?

I have a gateway p-7805u laptop with a Hi-Definition (HD) Audio chipset. i have 1 mic input port, 1 S/P DIF output port (shared with headphone port). usually, i plug in my headphones and listen to the sound effects as i play games online. recently, i bought an external sound card and a male/male 3.5mm stereo cable. since i have a newer version of vista, stereomix (or any other type of internal sound recording device) was not installed and cannot be used. so, i decided to "make" my own with the external sound card and male/male cable. i just plug one end of the cable into the mic input and the other end into the headphone output. but, when i go to record me playing my games, i cannot hear the sound (even if i have my headphones plugged in internally) since i have the external hooked up.

anyways, if i got a 3.5mm male to 2 RCA female audio splitter cable (instead of using the external sound card) and plug it into the output port on my laptop, plug my headphones into one of the female ports on the cable, and the male/male cable into the other female port of the splitter and then the other part of the male/male cable into the mic input port, would i be able to hear sound AND be able to record at the same time?