Would using OQL work for you? This is supported by Mendix.
https://docs.mendix.com/refguide/oql/
https://marketplace.mendix.com/link/component/66876
Could you not use contains, starts with, and/or ends with in an XPath constraint?
https://docs.mendix.com/refguide/xpath-contains/
https://docs.mendix.com/refguide/xpath-starts-with/
https://docs.mendix.com/refguide/xpath-ends-with/