[NTG-context] "Trial typesetting" in ConTeXt / lua ?

Dear all, Is it possible in ConTeXt within lua code to do “trial typesetting” (not sure that’s best name for what I would like to achieve) ? By this I mean store some input (with text and macros) in some buffer and do what ConTeXt does normally (parsing, create nodes …) but instead of

[NTG-context] % !TeX root problem

Dear all, I use product file: FM_main.tex which contains component files like FM_1.tex, FM_2.tex, etc. They are all in the same folder. In each component file, I put “% !TEX root=FM_main.tex” at the first line. It worked fine but some time after it won’t work. I know that it is a matter of

[NTG-context] can't find file `./1.tex'.

I installed in windows 7 x64 standatalone context from http://standalone.contextgarden.net/setup/context-setup-mswin.zip I installed it with first-setup.bat --version=current --modules=all I added d:\context\tex\texmf-win64\bin in the PATH I made a simple \starttext .. \stoptext file and run it in