[fptex] can one capture an environmental variable within a new command in latex?

[Luis A Escobar]

I would like to write a newcommand which captures an environmental
  variable defined in a windows environment. This could help me to
  write latex document that depend on environmental variables but which
  are basically machine independent in terms of paths, location of
  newcommands, figures, etc. Something like (but

  \newcommand{mypath}{\getenv{\$HOME}}

where HOME is an environmental variable pointing to a folder say c:\home

 Any help would be greatly appreciated.

  Regards, Luis A. Escobar
  LSU