AFAIK, there isn't a direct way to just watch certain addresses, but if you've got the private keys you can create a normal wallet and manually import the keys under Wallet Properties.
They'll be listed under "Imports" on that dialog once they're added. After that you can then convert the wallet to a watching only wallet by using "Export Watching-Only Data" (also on the same dialog).
If I'm wrong about any of this, I'd love to know