.NET CustomPage - Button creating new Oppo -> Redirect to Oppo after Saving it

Hello everybody,

we've got a custom page (tab underneath communication) showing additional information.
This is realised using a DLL (List, Filterbox, several Buttons etc.). -> Additional Table in 1:n relationship to Communication.

Now we've implemented an addtional button "New Opportunity" linking to the new Oppo-Screen (Act=1190).
I already compared the built URL within the DLL to the URL built via RightClick->New Opportunity.
After some customizations it is now exactly the same.

The problem we've got:

What can I do within the DLL (URL-generation for new oppo) to redirect to the newly created oppo after saving it? At the moment it depends on where you come from...

Example:

Login to CRM -> Search for a Communication -> Open DLL-Tab -> New Opportunity
After Saving the Oppo it redirects to the "Searchscreen for Communications"

But: It should redirect to the freshly created oppo.

I hope somebody has an idea...


Thanks in advance,
Robert.