If you wanted to really extend Shell.pm you might implement something like

use Shell cmdname => {
 exe => '/path/to/executable',
 capture_stderr => 1,
 params => [ '-foo', \1, '-bar', \2],
};
# ...
cmdname( $foo, $bar);
 # calling
 #  /path/to/executable -foo '$foo' -bar '$bar' 2>&1
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or even things like

use Shell cmdname => {
  exe => '/path/to/executable',
  return => 'pid',
},
 othercmd => {
  return => 'handle',
};
# ...
my $pid = cmdname(@params) or die "... $^E";
my $handle = othercmd( @params2);
while (<$handle>) {
 ...
}
close $handle;
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