SAP automation: How to activate Particular session

I am working on SAP automation.
I have to execute 6 different transaction code into 6 different SAP session.
for execute transaction code I already have 6 VB scripts.
I am stuck in how to activate a particular SAP session so I can run particular VB scrip on that.



Use the activity “Attach Window” on each specific window, each time you need to execute another activity over that SAP window/session opened.

Best regards.