Many thanks for your answer.

you can set the commands in context.properties file (or overload t hen
in your user.properties file)

But can you please be more specific? The only thing I want  is to press F7 and make the SciTE call
  texmfstart texexec --mptex < File.mp >
I tried to find the proper line in the context.properties file but I wasn't able to fix it. I uncommented the line 137, and commented the line 138 (now it is this:
  command.build.$(file.patterns.metafun )=$(name.context.texexec) --$(name.context.backend) --mptex $(FileNameExt)
  #command.build.$(file.patterns.metafun)=$(name.metafun.mptopdf) $(FileNameExt)
But it didn't help. What should I set, and where?

> P.S. Hans, would it be possible to add the Metafont into the minimal
> distribution? I like it so much I'd like to make it my major distribution

only the binary i assume? you also have to convince mojca, the minimal
gardener

Yes, I need only two things: binary Metafont (mf) being there, and pdfTeX (and later luaTeX) able to generate the bitmapped fonts on the demand. If you could add these two, I would instantly switch to the ConTeXt minimal distribution. It seems much better than both teTeX and TeXLive. Please, please. :-)

Many thanks for the great ConTeXt, minimal distribution (which saved me here in TeXas), and your help.
With best regards
Michal Kvasnicka