Linux/WINE/Lutris: importing registry data / .reg files into app environment

I’ve recently attempted to run a S.T.A.L.K.E.R. game mod, Call of Chernobyl, via Lutris.

That was quite a hassle, and certainly not obvious for people without knowledge of runtime environment variables, sync, paths, and other stuff …yeah, that ease of use certainly needs some additional refinement. -.-

However, i finally seem to have restarted Lutris for a sufficient amount of times, so that the game “actually” attempts to run. But now it’s greeting me with something like “Could not detect S.T.A.L.K.E.R.: Call of Prypiat license”. I own a license of that game …well, on Windows, via Steam. Here’s my idea; I’ve exported the Windows Registry branches of CoP (including all the leaf nodes [including the license key]) …i guess that’s what the mod is validating …how would i import those registry keys (myCoP.reg) into the Call of Chernobyl Lutris runtime environment?

edit00: nothing majorly important, a few refinement, prior to anyone replying

Someone, in TheLinuxGamer’s Discord channel, mentioned that i could achieve my goal by appending my exported .reg file to a user.reg within the WINEPREFIX.

Where is the WINEPREFIX in a Lutris environment? I understand it’s a path prefix, right? Is it my game directory, where my game files live, where i’ve installed / copied it? Can i just put a user.reg file right next to, e.g. my Stalker-CoC.exe?