Passing variables

[Alberto Manuel Brand�o Sim�es]

Hi
Makemaker supports things like 'perl Makefile.PL PREFIX=foo'
but, can I define new 'PREFIX' like options?
I've tried to catch it:
BEGIN {
  my $PARSER;
  $PARSER = grep { m!^PARSER=! } @ARGV;
  @ARGV = grep { $_ ne $PARSER } @ARGV;
}
use ExtUtils::MakeMaker;
but it didn't work.
Is this possible with current makemakers? Thanks
Alberto