BI-IP: Assign user input variable in planning seq. started by process chain

Hi,

I'm starting a process chain from a BI-IP planning web application. In the application there is a profit center drop down variable which I would like to assign in a planning sequence which is started by process chain. The process chain itself is started by a button in the web template.

So far I haven't found a place where I could assign the variable item to be used in planning sequence which is in a process chain. Any ideas?

Thanks!

Aki