[noimporta]

@Manichean thx a lot , it worked just fine.

But now a new problem came up. In the field tag I have all kind of info stored for some books and I want to extract the 13 character isbn to the identifier isbn.

A tag could be:

1234567891 1234567891234 :::: springer

I want to search the 13 digit isbn and store in the isbn identifier. I can match the 13 isbn but I don't know how to store it

[0-9]{13}

will match the 13 chars of the isbn... but then how do i replace? ;D

I forgot to add that not all tags are the same sometimes its

springer :: 1234123412341

so the regexp should find the 13 and replace it.