mixing modes

Hi all,

I'd like to create a new major-mode (for syntax highlighting, indentation etc.)
for files of a proprietary syntax.

In certain regions of these files, Perl code may appear. These
regions are delimited by the special character sequences
'{*' and '*}' (curly brace plus asterisk and vice versa). I'd like
to switch to Perl-mode in these regions.
How can I do this? (sorry, I'm a newbee to modes).

Are there any 'quick-start guides' or 'examples' on such a problem
or on major and minor modes in general?

Thanks for any help!
Regards,
Gerhard