I am not entirely sure if you are taking the piss, but OK, I will bite.
NMake has been deprecated for quite some time now, MSBUILD took over back in 2013 and is better, by and large, than NMake.
You can execute MSBUILD from PowerShell at any point in time, as long as you have you path set up to point to the correct version of MSBUILD (you will have a separate exe for each version of .Net you have installed, or explicitly call the one you want).
Alternatively, try PSake, its a PowerShell based build engine. Its actually OK, the build is defined as code as opposed to mark up, which makes it quite powerful, along the lines of Rake etc.
Biting the hand that feeds IT
