Try the following:
Open a command prompt with administrative permissions:
mklink /D Virtual_Folder_Here Real_Folder_Here
Example, you want to install something to D:\Games, but you want it to appear as C:\Games.
mklink /D C:\Games D:\Games
This will create a folder D:\Game which also appears as C:\Game. Anything that references C:\Game will be redirected to D:\Game.
Since I am not completely familiar with steam, I have not given an example that matches your exact folder. If steam allows you to pick the folder it installs to (Which due to you not just installing it to the other drive, I am not so sure it does.) you could create they symbolic link first. If however it does not, you may need to do some file-transfers, moving it to the new location and then creating the symbolic link. Example:
Steam installed your game to: C:\Program Files\Steam\SteamApps\common\Game2
Now, you create your folder: D:\GameGoesHere
Then, you copy all the files from the original folder and put it in D:\GameGoesHere, then you can create the link:
mklink /D “C:\Program Files\Steam\SteamApps\common\Game2” “D:\GameGoesHere”
Notice I used quotations this time due to the spacing of “Program Files.” Also note that before creating the link the virtual folder must NOT be a real folder. So, if the folder you want to be a link exists, you must delete it first (Not before you copy it, of course!)