RE: Workflow on Extender window
By default, there isn't any Workflow conditions for approval related to Extender being its a third party product.
That said, if you want to test something, you can add the following line to your Dex.ini file for Dynamics GP:
QueryDesignerAllFunctionality=TRUE
Once you do this, log out and back into Dynamics GP and when you go into a workflow step in the Workflow Maintenance window and click on the lookup to open the Workflow Condition Editor window, it'll have additional tabs besides the default 'Conditions' tab:
--Select Fields - this tab allows you to drill down under any module and series, and add any table and table columns you want to add, so you can use it in the approval condition query you can generate using this added functionality.
--Link Tables - this tab allows you to link fields on different tables when building your approval query, such as when setting up a SQL query.
--Run Query - this tab will have the overall SQL query you generate with the Select Fields and Link Tables and Conditions tabs, you can execute the query here to make sure it runs successfully or shows error messages.
This added functionality will allow you to use any module/table/column value you wish, in a Workflow approval condition, though with any customization, there's no guarantees this will work and not something we would support/assist with the setup.
Thanks