Direct hyper links to customer/contact cards

Hi

I am using NAV 2009 R2 RTC client and need to be able to link directly to a specific customer/contact card from an external application. I know I can use the dynamicsnav:/// handler to open the correct page but not with a specific customer/contact unless I use a bookmark which I do not have.

I have used the web service (from c#) to retrieve the customer/contact I want to open and have the contact/customer number. But how can I convert this to a bookmark without having to create a codeunit. Ideally I could do with being able to call  FORMAT(RecRef.RECORDID,0,10) via the webservice.

Is this possible or if not do I have any alternatives?

Thanks

Ben