rumcajs

Hi, I bought Legend of Grimrock from Steam and the game works fine. However, I'd like to try some mods as well and that's where the problems are. I have downloaded and installed the Nexus Mod Manager as well as a bunch of mods, but when I try to activate a mod it says "no custom launch command has been set" whenever I chose the "Custom Legends of Grimrock" option. I can choose the non-custom option and start the game via the manager without problems, but of course that means there are no mods activated. Could anyone help me with this? I got some mods working via Steam Workshop, but some of the mods I'd like to play aren't there. Also, how do I start a mod manually? Somewhere I've found that I put them into /Dungeons folder in the main Grimrock directory, but that doesn't work (I've tried with both zipped and unzipped mods).