[GRASS-user] [GRASSLIST:1168] How to select (and extract) a heep of entries of a theme

[wqual]

Hi list,
I have a large point theme (representing addresses with a column for the 
street, housenumber, ...), from which I would like to extract (using 
v.extract) only few. Therefore, I am looking for the best way to do so. Is it 
possible to select the entries step by step (something like add to current 
selection) and then extract the complete selection? 
I am asking this, because I find it hard to write down the whole sql-statement 
in one command (and therefore a growing likelihood of making errors).
Or can I store the sql-statement somewhere and re-use it with different 
commands?

I would be happy to read your suggestions!
Best regards,
Wolfgang