Defaulting warehouse based on business unit, customer and primary salesperson using extension

Summary:

We have a business requirement to default the warehouse attribute on sales orders based on business unit, customer and primary salesperson and we cannot find the Primary salesperson attribute.

In the Manage Pretransformation Rules for Sales Orders task, we cannot find the Primary Salesperson attribute in the sales order header.
is it possible to achieve this requirement using extension?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):