How to add a shortcut to a non-Steam game
- Launch Steam.
- Click the Games menu, choose Add a Non-Steam Game to My Library.
- Browse for games on your computer or put a check next to the game(s) you wish to add to the Library.
- Click Add Selected Programs
This will only add a shortcut to your game in the Steam client. This will not allow you to download updates for your game through Steam nor allow you to use this game as proof of ownership for your Steam account. Only games purchased or registered through Steam can receive automatic updates and function as proof of ownership for a Steam account.