I would like to find a way to update a specific field when certain criteria is met. Currently,  I am using a hosting server to map orders to the deals module in the CRM. At the time the orders are imported, they go into the booked stage.

Upon shipping the goods, I receive several invoice reports and mass update the invoice information for the coordinating deals by importing an excel, which providing updates on the invoice number, invoice date, total of the order that was invoiced, and the rate paid for the coordinating order. In efforts to be sure that I was compensated correctly, I have added a few custom fields (SHIP - COM 1) that will calculate what I was supposed to be compensated so that I can compare what is paid out by the vendor (INVOICE PAYMENT - BRAND). 

Yes, I could cross-reference the report to identify any discrepancies but I am hoping to automate this process so I can quickly uncover variant totals. In addition to the custom fields mentioned above, I have added three checkboxes -- Paid in Full, Partial Payment, and Overpaid. 

If the totals reflected in SHIP - COM 1 and INVOICE PAYMENT - BRAND match, I would like the system to automatically check the box 'Paid in Full' 

If the total reflected in INVOICE PAYMENT - BRAND is less than SHIP - COM 1, I would like the system to automatically check the box 'Partial Payment'

Initially, I thought that I could create a custom field that would generate a percentage (INVOICE PAYMENT - BRAND / SHIP - COM 1) and based on that percentage, update the checkboxes accordingly, however, since the SHIP - COM 1 is a custom field, generated by a formula, it cannot be taken into consideration when building out the custom field. 

Any suggestions would be greatly appreciated as it seems that I have hit quite the wall. Attaching screenshots for reference. Thanks in advance.