my %commands =
  (
   command1 => {
		 description => "Does something",
		 function => sub { my $var = shift; print "var = $var\n"}
		},
 )

my $cmd = 'command1';
$commands{$cmd}{function}($param)

##</code><code>##

my $func = \&version1;
is($func($param), 0, 'makes sense');

my $func = \&version2;
is($func($param), 0, 'does it ?');

sub version1{[some code]}

sub version2{[some code]}