SSO with Webgui and ~transaction=MM03

We use SSO for SAP GUI and SAP Webgui and it works fine for both. In the case of webgui we call first the service sapntauth.srvc which is then redirected to the service webgui.

Is there any possibility to pass the transaction as a query string when using SSO? This works perfectly fine without SSO, e.g. [http://<hostname>/scripts/wgate/webgui/!?_{transaction=MM03&}client=002&~language=en]

But in combination with SSO the only way to call a transaction directly was by creating individual services for each transaction. Any hint on how to do better would be very welcome.

We use SAP ITS 6.20 Patch 23.

Regards,

Gerald