Small command-line tool to generate NAV codeunit to call default lookup/drilldown forms for RecordRef (RecordRef/FieldRef is good functionality but some things are unfinished).
Resulting codeunit contains one Method called "LookupDate(VAR RecRef : RecordRef)".
You need just export NAV tables as text, generate codeunit, import codeunit back to NAV and compile.
Sample is included. Tools works only with tables with LookupFormID/DrillDownFormID properties set.