Change data in select rows when one is changed

[JMacFeegle]

For a little homemade CRM, I have one table listing in- and outbound emails. The table contains, among other things, the GMail message ID (key) and the thread ID.

I am manually sorting these mails to the respective projects by changing the project ID field.

Now, if I change this information (project ID) for ONE mail, I want my Bot to do the same for all other mails in the same thread. I'm assuming that will be done by running an action on a set of rows, BUT I can not figure out how to set up this action.

Bot trigger: Data change

Condition: [_THISROW_BEFORE].[ProjectID]<>[_THISROW_AFTER].[ProjectID]

Process: Run a data action

Referenced rows: select(Mails[Key];[ThreadID]=[_THISROW].[ThreadID])

Referenced action: ???

Any hints that might remove the blockage in my head would be appreciated, thanks!