Korg, I think the place to start with 'Artifical Lifeforms', is that PDF file on the subject (it's linked at a couple places on the board). Now it doesn't have Exocomps, but with it's general info on androids, holo-characters, and the like, it should give you a healthy shove in the right direction...
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...and that's about the time it hit the fan...
If you want to make an artificial lifeform, than just use the regular character creation process. If you look into the "The Price of Freedom" sourcebook you will notice that the stats for Data are not all that different from anyone else. He just has some unique restrictions and benefits.
To give a little background, especially for an exocomp, also do a workup for Alien Races and Alien planets (found in the back of the core rules books). You can develop a better idea for: what the lifeform was designed for, who designed it, why they designed it, etc.
If none of the advantages/disadvantages work for you, make a couple up. If it works for you, then you can email us and share. Who knows, maybe more dialogue will help you flesh out your ideas a little more.