Retrieving a column comment

Hi,

I can't seem to retrieve a comment on a table column. The following copy from
psql should I think return a comment:

====================
mydatabase=> COMMENT ON COLUMN car.manufacturer IS 'manufacturer name';
COMMENT
mydatabase=> SELECT relnamespace FROM pg_class WHERE relname='car';
 relnamespace
--------------
         2200
(1 row)

mydatabase=> SELECT col_description(2200,1);
 col_description
-----------------

(1 row)

====================
i.e. it just returns a blank row.

The col_description is described at
http://www.postgresql.org/docs/7.3/static/functions-misc.html
The field number supplied above '1' is right if the first col in a table is
'0', in fact no number I've tried returns anything.

I can't seem to find any examples at all on the web about retrieving column
COMMENTs. Has anyone done this? Postgres version is 7.3

Regards,

Oliver Kohll
GT webMarque
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