How do I link the PSN/Steam account on Portal 2 and my Steam account here on PC?

[ZIKKY!]

Ok, so I've been searching for the answer to this for a while, and haven't found one. I bought Portal 2 for PS3 and it came with a code for the Steam version (you know, on PC.). Recently, I tried logging into my Steam account on Portal 2 (on my PS3) and it pops up with an account that has my PSN name and all, not even asking for an existing Steam account, etc. (Probably because it's just my PSN account? or is it a Steam account? I can't find it here on Steam. Or log into it.) So, now, I can't really redeem my code here without completing Portal 2 for PS3, but I honestly don't know how I am supposed to do that if my PS3 doesn't want to cooperate with me, and Steam doesn't want to link to my PSN. (Which, in fact, I have no idea how to do because everything I find is outdated.) So, in the end, I can't play Portal 2 on PC and have fun with community levels.

So, just to simplify for those who have small attention spans, how can I use my code that came with my PS3 copy of Portal 2?

Please do explain in detail. I am an idiot.

[󠀡󠀡󠀡󠀡󠀡󠀡󠀡󠀡󠀡󠀡]

if you have steam code for portal 2
Launch the Steam client software and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam...
Follow the onscreen instructions to complete the process.

[ZIKKY!]

Originally posted by ♤ FeArSoFLoVE ♤:

if you have steam code for portal 2
Launch the Steam client software and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam...
Follow the onscreen instructions to complete the process.

Thing is, though, I have to complete the game to redeem the code and Steam doesn't have a way of verifying I completed the game. Steam itself says that I need to play it on the PS3.