I do something similar using Bicommand. I placed Bicommand.ex in in C:\Program Files (x86)\
Blue Iris 3\BIcommand\
Under the Alerts tab, Run a Program, Configure button-
In the file box enter... C:\Program Files (x86)\Blue Iris 3\BIcommand\bicommand.exe
In the Parameters box enter... ptzpreset=2 CamShortName
Check the box... Run file again when trigger is reset
In the second Parameters box enter... ptzpreset=1 CamShortName
This method returns the PT camera to its original position.
I use it on a PT camera in the house that looks over the living room normally. When the outside front door cam is triggered it moved the PT camera to look at the inside of the front door. And I do the same thing when the back yard cam is triggered the PT moved to look at the sliding door to the back yard.