Hi Marina,
This is definitely possible by using variable replacements. See the following link for a reference of different variables that can be swapped out of a custom item: http://www.empirisoft.com/medialab/h..._reference.htm
Have you tried running through the sample custom items yet?
In order to write responses from a custom item, that can later be used by DirectRT, you would need to write a small custom application.
Does this help?
Regards,
Trevor