Open outlook item from website

[Philipp]

I have an Website which needs to open a outlook contact item. Until
now with office 2003 I used the "outlook:entryid" functionality to
achieve this. But with outlook 2007 this works no longer. I know that
I can do the same with the following command
outlook.exe /select "outlook:entryid"
But this is no solution because you can't execute such commands from a
web page. Does anybody knows a solution for this problem? Is this
possible without installing anything on the client machine?

Thanks in Advance
Philipp