> Here's how I've done this. Let's use your embedded chr_is_num call,

Thanks for that, nice lateral thinking :)

I am trying hard to :
- not use SP's at all
- if SP's are indicated, not use UDf's

As I am writing an application that targets multiple DB's (Firebird
(yay), Oracle (yay), MS SQL (yuk)).

This is definitely a good way around the limitation of substring
thanks.

Regards,
Jono.