Yes, you should be able to do this. On CallManager 4.1 (probably similar for previous versions) the personal directory web pages are located in C:\CiscoWebs\IPPhoneServices\PersonalDirectory. Change the ASP pages to remove the New softkey.
I believe that the change is in the xmlAddressBookSearch.asp file. Search for lblKeyNew and you should see where the softkey is written to the ouput (in two places). You can comment out the two softkey definitions and that may give you what you're looking for.
When you upgrade your CallManager you will lose these changes, and these changes are unsupported by Cisco.
