How to fetch parameter from url

How to fetch parameter from url

Hi there.

I have an application (a sample is available on https://creator.zoho.com/zoho_dhl/dhltest/#) where I want to send my users a URL with their userid so my form can fetch the ID and fill out part of the form up front.

So I would like https://creator.zoho.com/zoho_dhl/dhltest/#Form:RMA?User="Happy User" to result in disabled User field being updated with "Happy User"  (and then having my deluge script finding the email for that user etc. etc.)

But I cant seem to pass on the parameter to the lookup field ?! 
(I can send the No or the Email, but not a value to a lookup...)

Can anyone shed some light on this ?

Thanks,
David