Windows CMD sort retaining header?

Need to sort in Windows a large CSV-like file with a header row (~7 million rows). Can successfully do this with a CMD command sort, but it includes the header row in the sort. I would like to keep it at the top.

I also have Notepad++ which has a sorting feature, but it fails for my two largest files (bug reported).

I am open to both suggestions involving CMD sort command and other solutions, preferably ones that can be scripted in CMD or PowerShell (which I'm not so good at yet).