This feature is only available with Saleslogix 6.2/7.0/7.2/7.5. A list item in an F2 Lookup can be setup to retrieve information from your contact manager.  For Saleslogix you can retrieve account or contact information. For a list of fields that you can use go into the DataLink setup where you add a new field mapping and in that drop down you will see a list of all the fields that you can retrieve information from.

Example:

~SLX_Macro(contact->homephone)