windows - Passing parameters/values from Emacs to external application -

i'm working on plugin niche cad application our company uses. development environment entirely based on emacs , should done through it.

in case, code should edited, navigated, compiled , debugged using emacs. there no separation emacs , actual language compiler (from know far - there no compiler.exe).

since team not fan of emacs trying rid of dependency can use whatever editor want compile/interact application without emacs, looks hard because built inside it, go-to definition, find references , sorts of commands.

these defined in hundreds of .el files (lisp) called using custom commands emacs.

however, when calling "run file" example, said file ran inside application , correctly executed question is: mechanisms used used happen? don't expect precise answers can't share name of actual cad application or else, helpful understand options possible can investigate them.

in summary, whenever "run file" actual application started emacs calling command line , actual file gets executed inside application. looks contents of emacs buffer passed application somehow. "how" i'm trying find.

thanks help.