How to pass parameters to a module

[Rajesh Dorairajan]

Can someone explain how does one pass a parameter to a Perl Module? To
illustrate suppose I've My::Module

package My::Module;

BEGIN
{
  $scalar = $input;
}

use Exporter;
our @ISA = qw(Exporter);
our @EXPORT = ($scalar);

In the above script is there anyway to pass the $input variable to the
package My::Module from the calling script? Please excuse me if the code is
horrible, just trying to simplify what I want ;)

TIA

Rajesh