Using Web Object to Record and Save User´s Text Input in a DB

I want to build a game like journey to build a character for a role play online social game... I want to build this journey using all the interactivity and content features available with the Articulate tools. 

To record, for example the Mission of the character that the user is building through this journey, the user will have to go through a number of challenges, at the end of which, the  system will present a large text box to record the user´s stated mission.

So, I could use a Web Object to do that and insert the HTML page with the proper form, but how do I pass the session information related to that user so that the answers gets recorded correctly under his/her username?

How can I do that? Is a Web Object the best way for an outside app to interact with Articulate?

TY