Add SC Custom WebDynpro Form in standard process

Hi guys,

I created a custom Web Dynpro application for adding items to a SC (with extra fields not available in a standard SC creation). I will need to create a webservice to add it to the SRM portal (still didn't do that).

Once the user is inside the custom WDA he'll have a button "Add items to SC" and at that moment we need to go back to the standard SC creation with all the items he inserted in the custom WDA.

My question is, how do I go back to the standard SC creation screen and how do I send to that screen all the values entered in the custom WDA?

Do I need to use some sort of Outbound Plug from the custom view I created? Do I need to place some code at the moment the user clicks on "Add items to SC"? Is there any special FM/structure that I need to use?

I saw at one old development that was using some kind of BSP cache stuff...is there something new that can be done avoiding that?

I'm not too experienced in SRM, that's why I'm kind of lost here!

Thanks in advance!

Matias