Rather than manually create the Excel file for subscriptions let SSRS Subscription manager do this for you.
By creating a blank subscription it will allow you to confirm the parameters in the report.
Tip: an alternative option is to create a single subscription in Report Manager and then backup this subscription. With the excel file you can now copy this subscription multiple times. This is the quickest way to create subscriptions in Reporting Services.
this option is located in the Backup subscriptions screen
