Welcome to the forum!
Hhmm, I had to look up the NC file format. Looks like a format used by CAD software, right? Inkscape is not CAD software, and doesn't support NC. I guess that should probably answer your question?
I'm not really clear what you're trying to do with headers and footers....especially related to CAD software. I think of headers and footers related to text documents.....or also webpages. But I don't think of either text docs or webpages as related to CAD.
But if you want to use Inkscape for whatever you're doing, please explain more about that, and we'll be glad to try and help.