Excel 2007 : Conversion of Alphanumeric Value to Only Numbers

Alright, so a bit of background information, I'm creating an index of wireless networks around my neighborhood with the overall goal of [eventually] being able to identify my location using only the signals around me. To do this I am logging the MAC addresses (The unique alphanumeric assigned to every wireless device) of networks at a numerous points (Like, every other house) up and down my street with the house number and all of the MAC addresses my computer can see. From there, I dump it all into Excel, delimit the addresses (Which start out looking like this "c0:83:0a:96:2e:b9") by colons the so I've got the two character pairs spread out over 6 columns. Lastly, I add up the columns and find the correlation with the same sums from my unknown point.

Now, what I'm having trouble with is, as unique as the values this gives me are, they're not unique enough. I need some way to convert the letters from the MAC addresses into numbers so I can factor them into my calculations, I don't care if they get multiplied or added with the other number in their column, as long as they're part of the end value.

Hopefully that makes sense; any suggestions?

TMShucks:
Fantastic!
That'll probably work, thank you.

shg:
It gives me a unique identifier for each location, that I can cross check with the unknown location.