memberlist hook

I’ve been working on a complex site that requires a mechanism for relationships between users i.e. student -> educator. Where the educator has access to certain student files.

Students nominate their educator themselves and this is all done through an extra database table and patching the mod.member.memberlist and model/member.php file in the member module. This is to allow the control panel Members section to be able to cope with the extra field (‘nominated’) required in the SQL query to check if an educator has been nominated by the student and to add an extra sort field called ‘Nominated’ to the Member List in the standard member module.

I’m now wondering whether I could write an extension using a hook to achieve the same functionality because every time I upgrade EE, the above files need to be re-patched. But I can’t see a hook in the library that would give me access to what I need.

Is it possible to write an extension to achieve this, and if so, where would I start?