Help Using Schedule To Update Records

Help Using Schedule To Update Records

I'm using Zoho Creator to report on data from a different software application.

I have 2 forms that were created by importing records from CSV files.  The first is Player_Invoices and the second is Player_Payments.  Each table has a field named Bill_ID (which is a string).

I've created a subform on Player_Invoices that I want to display the Player_Payments.  I would like the subform to display all the payments that match the unique Bill_ID field for the invoice.

I assume that in order to do that I will have to connect the Player_Payments form to the Player_Invoices field via a lookup. I've done that.  

Now, I need to run a Custom Schedule (one time) to update the Player_Payments lookup field with the ID of the Player_Invoices record where the Bill_ID is the same (there might be multiple entries that have the same Bill_ID. All the data is already in the table.

I'm not a coder and very new to Zoho Creator.  I attempted this, but it is not updating anything:

  1. r = Player_Invoices[Bill_ID is not null];
    for each x in Player_Payments[Bill_ID == r.Bill_ID]
    {
    x.Player_Invoices=r.ID;
    }

Any help would be appreciated.