my $modname = "mod_1";  # dies wird übergeben
use lib "modules";             # folder der Module
use $modname;               

my $module_dir = 'modules';
my $module_name = 'mod_1';

require $module_dir.'/'.$module_name;

my %divs;
my $content;
my $mod = "modules";
push(@INC,$mod);
require "$mod_1.pm";
&$mod_1();

sub start() {
   $content = "test";
   $divs{'test'} = "test";
}
1;

package Module;

sub start() {
  my ($content, $divs) = @_;
  $$content = "test";
  $divs->{'test'} = "test";
}
1;

Module::start(\$content, \%divs);

my $mod = "blabla";
eval "use $mod";

my $lib;
BEGIN {
  $lib = "foo/bar";
}
use lib $lib;