Microsoft have a useful repository of Perl snippets at http://www.microsoft.com/technet/scriptcenter/scripts/perl/prlindex.mspx unfortunately this does not have Perl versions of all the VBScript snippets, however the specific incantation you need to change the password in AD (in VBScript) is at http://www.microsoft.com/technet/scriptcenter/scripts/ad/users/pwds/uspwvb02.mspx so I guess that the Perl version of that will be something like (untested):

use Win32::OLE;

my $userobj = Win32::OLE->GetObject('LDAP://cn=myerken,ou=management,d
+c=fabrikam,dc=com');
$userobj->ChangePassword('oldpass', 'newpass');
[download]

Obviously you will need to change the details for the user.

/J\