Hi. For your particular case you do not need regex at all. Simple substring + position.
Example:
Select
D.NAZWA
, SUBSTRING(D.NAZWA FROM POSITION('V', D.NAZWA)+1 FOR POSITION('p', D.NAZWA)-3)
AS V
, SUBSTRING(D.NAZWA FROM POSITION('p', D.NAZWA)+1 FOR POSITION(' ',
SUBSTRING(D.NAZWA FROM POSITION('p', D.NAZWA)))-2) AS P
from
(SELECT 'V12 p234 The state of the nation.pdf' AS NAZWA FROM RDB$DATABASE) D
Pozdrawiam,
Karol Bieniaszewski
