How to pass Dynamic Paremeters into Web Dynpro URL

Hello Friends,

                      I have a requirement to pass a value along with my Web dypro URL  dynamically. I know how to read a value from the URL but not how to pass to it. Your help is greatly appreciated.

EG URL: http://vuapps05:8000/sap/bc/webdynpro/sap/ZFORM

I need to concatenate a dynamic parameter to it .

Thanks,

Vishnu