If all your .sh file does it set environmental vars in a static way (no conditional statments in the .sh, etc...) you could just read and parse the .sh file to set your %ENV vars.

open F,"<conf.sh" or die $!;
while(<F>){
  chomp;
  if($_=~/([\w\_]+)\s*\=\s*(.+?)\s*$/){
    $ENV{$1}=$2;
  }
}
close F;
[download]

or something like that.....