Hi there and welcome Les
To do this, Go to the public folder contact list properties (right click it) and select "show this folder as an e-mail Address Book". Click ok. Now go to the address book [icon on the toolbar] and go to Tools, Options, Change the search order and also select the public folder address book as the default one.
If you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.