Bulk Read - Record Count

Bulk Read - Record Count

Hi all

I want to set up a CRM schedule that counts the records in a custom module that meet certain criteria and record that number in a field on my Accounts module.  As there are more than 200 accounts and the number it will be counting is more than 200, I think Bulk Read is the only way to do this.  My problem is, I just can't get my head around creating the query. 

Once I understand the structure of the query itself, I am fairly confident in my ability to do the rest.  Is there a simple way to structure/build a JSON list, that makes sense to people with limited technical skills/mental capacity? :)

What I want to do is:

a)      Bulk Read all Accounts
b)      Iterate through each account and then do a Bulk Read on the custom module where Account = current account iteration, Status = [Whatever] and Created on is current month
c)       As in b, but for previous month

Any thoughts, help, tips would be greatly appreciated.