support of input ready BEx variables in DS

Hi experts,

I just went through hand-on session on SAP BOBJ Design Studio 1.0 as shared on last year TechEd.

It was said in session that Design Studio is not supporting mandatory BEx variables. There is also workaround suggested to set those variables with default values and then use scripting in Design Studio in order to manipulate value of variable.

Can someone having experience with mandatory BEx variables share details how this would be implemented?

thanks, martin