Google came up with a number of methods to convert bbcode to html, but not the other way around.
Unfortunately I'm not that well-versed with regular expressions. Maybe someone could give pointers?
Some options I have are:
PHP - This article, Simple and Complex BBcode with PHP, uses str_replace to convert bbcode to html:
CODE
$string = 'This is [b]cool[/b] - [url=http://www.tutorio.com]Tutorio.com Tutorials[/url]
$bb-replace = array ('/(\[[Bb]\])(.+)(\[\/[Bb]\])/','/(\[url=)(.+)(\])(.+)(\[\/url\])/');
$bb-replacements = array ('<b>\\2</b>','<a href="\\2">\\4</a>');
$string = preg_replace($bb-replace, $bb-replacements, $string);
print $string;
Textpad - Maybe a macro could handle this.
$bb-replace = array ('/(\[[Bb]\])(.+)(\[\/[Bb]\])/','/(\[url=)(.+)(\])(.+)(\[\/url\])/');
$bb-replacements = array ('<b>\\2</b>','<a href="\\2">\\4</a>');
$string = preg_replace($bb-replace, $bb-replacements, $string);
print $string;