Secure dynDNS-Update with Router

Hi, i want to update my SuSE 8.2 / BIND 9.2 DNS-Server dynamically with TSIG-Keys. Is this possible, if the Client is behind a router? The Netgear RP314 ADSL-Router, as an example, has a builtin DynDNS-Client which happens to work only with dyndns.org (they don't use TSIG-Keys for authorisation). Exist any routers which are able to handle custom dynDNS-servers with TSIG-Keys? Best regards and thanks for any help Andy