[0-9]{2, 3}
\d  - decimal [0-9]
\s  - space \t \n " "
\w  - word character
[a-zõäöü]
\w+
\. - punkt
\d{3} [A-Za-z]{3}
\d{3} ?[A-Za-z]{3}[\.\s]

Asendus:
 (\d+) 
kogus \1 tk 
([0-9]{2})\.([0-9]{2})\.([0-9]{4})
\3-\2-\1