How can i get dragon age origins to show up on steam?

I went to gamestop after work today and picked up dragon age origins. i installed it and it shows up on the desktop and i can play it, but for some reason it doesnt show up on steam and i can't open steam while im playing it. can someone help me out because im not sure what i need to do, thanks.How can i get dragon age origins to show up on steam?
i would you suggest you can go with Star Ocean: The Last Hope International

If you love good RPG games star ocean is one of the best. I played the last one for ps2 and loved it so I had high hopes for this. Turns out it lived up to everything and more. I played this for xbox but recently purchased a ps3. The Major difference that I see is that this game is all on one disk unlike the xbox version which you had to keep switching disk. That alone is enough for me to purchase this game for ps3. Gameplay wise this game is too good from its active battle systems to the very likeable characters and its quest and storyline. Any person who enjoys RPG's as much as i do should love this game. 5 stars all the way!!