# Create connection
my $SSH = Net:OpenSSH->( $IP, user => 'user', password => 'pass' );

if( !$SSH->error )
{
     # Is my process running?
     my $PROC = $SSH->capture( "ps aux | grep <process_name> | grep -v grep | wc -l | sed 's/  *//'" );

     if( $PROC == 0 )
     {
          # 3rd party program is run here via perl system method
          # If it happens to fail, it has no adverse consequences on
          # the rest of the script.
          <run 3rd party program>
   
          if( <my above 3rd party output condition is met>  )
          {
               # Read File on remote machine
               ( $DATA, $ERR ) = $SSH->capture2( "cat <file on remote machine" );

              # Write/Append $DATA to loca file
              <write data to loca file>

               # Delete the remote file
               $SSH->system( "rm -f <remote file>" );

               # And finally, since my remote process is not currently
               # running, spawn it on the remote machine
               $SSH-spawn( "./script.pl" );
          }
     }
}
else
{
     print $SSH-error
}