Using excel to cross-reference growing list of names and numbered ranges per month?

We use a small-ish list of names that get assigned a numbered range that shuffles each month and is logged in an excel document. I inherited this and it's been just manually checked over but is there a way to have excel look at the old lists and either populate a new list without any numbered overlap or highlight when there is an overlap entered? I mostly just need to know if this sounds possible, and where to start if so. I'm a pretty basic user so I'm not really sure what verbiage to use to start looking things up properly