I use Steam to run World of Warcraft, but WoW is not a Steam game. Since I can't bind PrintScreen as the screenshot key in Steam, I can't take a Steam screenshot at the same time as I take an in-game screenshot. Also, I have an addon in WoW that automatically takes screenshots given certain conditions. Having the screenshots allows me to use Steams browser to navigate screenshots, as well as use them as a background on the game's Libary page.
Is there a way to simply attach World of Warcraft's screenshots directory to Steam's?