hm, basic.dll is the file that should be created, but c:\mdlapps will probably not exist.
I asked previously who suggested the call into mstndevvar from another cmd file. You will end upp with missing settings, because as soon as mstndevvars is closed some of the variables are no longer valid.
Use the suggested way and open the developer shell, start bmake from there ! Normally the destination for your created dll is $(mdlapps) (usually <ustnpath>mdlapps/ ). If this could not be resolved correctly you might end up with c:\mdlapps