MySQL help - isolating a substring

[MacMorag]

Working directly on the database via phpmyadmin, how do I extract "XXXX" from the following string. I will store "XXXX" in a new field:

String:

abcabcabcabc[pic]XXXX[/pic]abcabcabcabc


the "abc..." bits are variable, but there is always one instance of [pic] and [/pic].

I'm guessing that I need something that creates a substring after "[pic]" and before "[/pic]" - but MySQL knowledge is not too great yet :ermm:

I've had a look at www.mysql.com but can't find the answer.

Thanks for any help.

Morag.