I'm working on solution that will send email notifications on a scheduled basis to customers to fill out a survey via a link to a Zoho creator form.  The survey form data needs to be related back to the customer form, so I've placed a lookup field on the survey form to accomplish this.  

I need a way to include the customer ID (the value of the lookup field) in the link so that the survey form can be related to the customer without prompting for that information.  Using the standard "?customer_lookup=000000000" syntax in the URL, is not working.  

Any advice?