You wish to be able to run a command stored in your shared vault but with your own set of credentials instead of those set in the entry.
The User Specific Settings feature does not give you access to the Run As tab.
Configure a Command Line session.
Click on the Run as tab and set the Credentials to Current session then click OK.
In the Edit - User Specific Settings window, override the credentials and enter your own set and click OK. This is the result from our example: