PQgetvalue and User defined types/Arrays fields

Hi everybody,

I'm using Postgresql 7.03 (but I'm going to migrate soon to 7.1) and I have
a big doubt about how to work with User defined types in my tables using
libpq and the documentation does not help at all.

Anyone have any sample about how to use libpq with PQGetValue or similar to
read records which have fields defined as Arrays or User defined types?. I
looked for samples in the documentation or in the mailing list but I
couldn't find anything.

For example, if I define the user-defined type "complex" just like in
http://www.postgresql.org/idocs/index.php?xtypes.html#XTYPES-USERDEFINED and
then I use it in a table, how can I read the field?. Must I use the
complex_in(char *str) function passing as a parameter the PQGetValue result
associated to this field number?. I have the same doubt when I define an
array field.

By the way, do you know if there is any documentation/sample about libpq
explaining these more advanced topics which are not fully explained in the
general documentation?

Best regards and thanks in advance,

Jordi