Base type OIDs

I'm trying to properly tag the types of the parameters I'm passing
into PQexecParams, as it seems to be the right thing to do, and it's
not that big a deal given my existing code base. Unfortunately I'm
running into a problem figuring out what I should be using for the
tag numbers.

I originally thought that the enum in include/ecpgtype.h was the
place to go, but no joy there -- those numbers weren't right. (Or at
least they threw errors) So instead I tried
src/include/catalog/pg_type.h for the type numbers. (Which seemed a
better bet, as the docs for PQftype say to reference this file)
Unfortunately this isn't working either. I'm trying to use these base
type numbers:

     text data: 1043
     numbers: 1700
     dates: 1082

which correspond to the VARCHAROID, NUMERICOID, and DATEOID
constants. It *seems* right, but when I do I get back the error:

   DB error is: ERROR:  unsupported format code: 1043

I'm at a bit of a loss right now. What *should* I be using here? (Or
is there something simple that I'm missing?)
--
                Dan

--------------------------------------it's like this-------------------
Dan Sugalski                          even samurai
dan@sidhe.org                         have teddy bears and even
                                       teddy bears get drunk