Beside the Libpath there is also the beginlibpath and endlibpath which can be set (though are not technically environment variables) before launching an application.
Theoretically, these should always work, but in practice, I have seen a couple of programs that ignore them. I don't remember which ones, but I think they may have been ports from linux. The only answer, that I know about, is to put the directory into the Libpath, and reboot.
Thanks both of you. I know a bit about how dynamic link libraries work. Usually dlls work in the application folder or actual system locations, like C:\WINDOWS\System32 At least that's how Windows has always worked, so what you two are telling me isn't completely foreign to me. eCS seems to work in a similar way, which makes things a bit easier.
As I pointed out before, OS/2 and WinNT (and up) are from the same roots, so there are similarities. Windows seems to be a bit more forgiving if you mix DLL versions though.