Preserve identifier case

PostgreSQL makes all identifiers to be lower-case except when putting an
identifier between double-quotes. 
I have an special case where I would like to preserve the case-sensitivity
without putting every column/table name inside double-quotes (The
application is too big to change).

Is this function the correct place to bypass the down casing for all
identifiers?  
http://doxygen.postgresql.org/scansup_8c-source.html#l00129

Regards,
Gevik
http://www.truesoftware.net/gevik/