Sage 100 2013 Restrict ability (permission, right, role) to change Salesperson in Customer Maintenance, Sales Order Entry, etc

SOLVED

Hi everyone, 

I'm using Sage 100 ERP 2013

Does anyone know exactly where (and if, even) I can limit users' abilities to change the Salesperson in Customer Maintenance, Sales Order Entry, and anywhere else where it's possible for them to do so? I'm having a lot of problems with people doing this at my family's small company. I hope I don't have to customize the panels in order to achieve this - that can't be, right? I looked, but had trouble finding what I needed.

Hopefully someone can give me a clear path to the exact right in Role Maintenance that will switch this on/off, if it's even possible to do this way. 

It looks like this is as far as it goes: 

I want to be able to control functions within the Customer Maintenance task (and others) but it seems that's as far as things go here.

Hopefully someone has a better solution than being forced to customize another panel. Is there a simply way to add a custom rule to Role Maintenance?

Thank you