Aastra XML access to system phonebook

I am after some help with an function i would like to do with an Aastra 6755i handset.

I would like to program a button so that it accesses the standard system phone book. I presumed this would be available but all i have found is the directory.php file which just lists internal extensions.

We have around 100 speed dials set in the phone book and all we want to be able to do is search them on the Aastra 55i handset and then dial the number.

Can anyone let me know how to achieve this.

Sorry i forgot to mention that i am using Asterisk with FreePBX and Astra XML scripts - aastra-xml-scripts-2.3.1-98fpbx