dump data into table with sequence

Given this table:

Table    = rechnung_kunde_199805
+----------------------------------+-------------------------------------+-------+
|              Field               |              Type                  
| Length|
+----------------------------------+-------------------------------------+-------+
| rechnungs_id                     | int4 default nextval ( 're_id_seq')
|     4 |
| kunden_nr                        | int4                               
|     4 |
| stream_name                      | varchar()                          
|    40 |
| offset                           | int4                               
|     4 |
| length                           | int4                               
|     4 |
| datum                            | date                               
|     4 |
+----------------------------------+-------------------------------------+-------+

There is a unique index on rechnungs_id and a sequence 're_id_seq'.

I want to insert loads of data into this table ->    'psql DB <
data.sql'
data.sql is like:  'COPY .. FROM stdin;'  __data__  \.
and the 'first field == rechnungs_id' in the data is empty (just a tab).

This doesn't work as PG tries to insert NULL as value for rechnungs_id
instead of 
using the sequence.

Q: Is there a way to solve that problem other then defining a trigger?
If not: 
Q: Can someone give me an example how to define the trigger (and the
procedure?) here?
I have read the docs (+ the contrib stuff), but still don't know exactly
how to
implement that.

regards, Tony

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Anton Stöckl                    mailto:tony@cys.de
CyberSolutions GmbH             http://www.cys.de
Frankfurter Ring 193A           Phone +49 89 32369223
80807 Muenchen                  Fax   +49 89 32369220
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