I do not understand the script, but a solution could be to first search for the files in `pwd` and if it is not in /opt/acroread123, after that make all operations there, as already is.
You could also make possible the selection of files through an argument after the command, and if not, tell to the user where the file will be downloaded.
Anyway thanks again, yesterday acrobat helped me a lot (especially for print settings)