Twin XLR into MIC jack on Laptop

[cookster]

I have recently accquired a Dell M6300 as part of a media role I am currently in, and one of the projects is to record audio coming in from 2 sources, left & right channel. I believe there is something called a XLR Box which fits into the mic jack and when recorded it forms a *.wav file. Could someone tell me where I can get these from, are they specific for the soundcard and what sort of cost we are looking at? Once the audio file has been recorded I can then place in the timeline from the video footage using Premiere Pro CS3.

Urgent response, be greatly appreciated!! Many thanks Elliott