Debhelper 9 is backported to squeeze (9.20120909~bpo60+1 in squeeze-backports), so you shouldn't actually need to modify the package to work with v8.
I have backported the sid package of Zabbix 2.0.2 to squeeze with a few minor changes (debhelper 8.0.0 not supporitng dh_uch), and was wondering what the best way of submitting this for approval\consideration for going in to squeeze-backports.
Thanks for your time,
C/ Quintanavides 15. Edificio 2, Planta 1ª
Parque Empresarial Vía Norte, de Metrovacesa
28050 Las Tablas. Madrid