I was able to run the scripts using tp command passed as a argument to Shell command. i.e.
Shell(tp -u admin -p admin -d Another_DSN -r Common -a -i -s sr1).
This worked without a hitch.
I also tried using the test partner API (by adding a reference to Testpartner library)and was able to access the details of various scripts projects etc. in the other db but the Execute command didnt work for me.