Good Day David and Juraj,
Thank you for the replies. I did a lot of thinking and now am going for the approach described by David.
1- Writing a custom module, due do freedom of desinging an interface, and the routing rules are global .
2- using a custom data table to store the configured rule(s).
3- using custom logic on submission of forms at client side to determine which email address(s) the notification routes to based on the options selected in the form.
Many thanks guys for your input .