Thankyou both (Suzanne and Graham) for your replies, they were both very
useful.

One further question although this may be TOO difficult, Suzanne says the
Custom Labels are defined in the registry and I have found the entries but
they are BINARY keys. Is there any way to decode these keys so that I can
change the indents on a Custom label (e.g. if byte 25 defines the indent I
could change it from 02 to 05 or something)