WAF IP Rules with more operators like "contain/does not contain"

Please broaden the operators for security rules under IP Address to allow ‘contain/does not contain’ etc.
This is because the dynamic IPv6 address on a mobile device has a static prefix and dynamic endings, so to access my firewalled site on that device I would like to add the prefix to the WAF security rules, and not have to constantly update the suffix every time it changes!