Additional Setup Package Creation in 800xA for Client PC
I suppose you are referring 800xA 5.1.
System Planner Tool does not give oppurtunity to create a package for single client for existing installation.
Suggestion would be to use System Planner to re-run the wizard and create the new package by filling all the details as per the exising system. This will create package for all the nodes in the system + additional client. OR Manual installation if number of system extensions are not large.