8.2 RETURNING functionality in a trigger

Hello,

I have searched unsuccessfully for the answer to this so I hope that one of
you may be able to help me.

I am using the new RETURNING functionality but can't make it work in a
trigger.

In psql I can run a query like this:
INSERT INTO foo(col1, col2, col3) VALUES (1, 2, 3) RETURNING col1;
and I get col1 back from the insert.

Now, when I do that in a C trigger via SPI_exec the SPI_exec succeeds, but I
can't figure out how to access the RETURNING part.

I have:
if (SPI_exec("INSERT ....", 0) < 0)
{
// fail
}
else
{
Datum test = SPI_getbinval(SPI_tuptable->vals[0], SPI_tuptable->tupdesc,
1, &isnull);
}

I have used similar code to get values from SELECT without problems. I
assumed that an INSERT RETURNING would place the returned value into the
global SPI_tuptable, but it seems that this isn't the case? If, right after
the SPI_exec, I check SPI_tuptable it is indeed NULL.

I guess my question is then: In a trigger using SPI_exec, how does one get
the RETURNING part of the query?

Thank you for any help you could offer,
Doug