href{run:textfile.txt}{Link to text file (line 20)}

href{run:/usr/bin/gedit +20 textfile.txt}{Link to text file (line 20)}

documentclass{article}
usepackage[utf8]{inputenc}
usepackage{hyperref}

begin{document}
  href{run:file.txt}{test}
end{document}

/A <<
  /F (file.txt)
  /S /Launch
>>

/A <<
  /Win <<
    /F (editor)
    /P (+20 file.txt)
  >>
  /S /Launch
>>