casting in xpath

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Is something like this possible?:

//Node[xs:int(@number-att)=$myNum]

My problem is that I don't know if @number-att will be padded with zeros
or not.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFFy4eZkAu83kdgE3MRAt1UAKCCWgeguQb2TbLa4pGCfi8DFAngwACgjH8N
37HtDlXgE+Y4/ZcHZcJtquE=
=aAJh
-----END PGP SIGNATURE-----