[Koha] Numeric range searches

[Cab Vinton]

I'm wondering if there's a way to do numeric range searches in Koha
3.0 (apart from the ability to search for date ranges in the catalog).

The 521 tag, for example, can be used to assign lexiles, reading grade
levels, interest age levels, and so on. Ideally, the OPAC should allow
a user to identify suitable materials for a child by retrieving items
within a range of lexiles, e.g., 420 - 500, and/ or range of reading
grade levels, e.g, K-2.

Has anyone implemented this? If not, how hard would this be for the
development community to implement?

Many thanks,

Cab Vinton
Sanbornton Public Library
Sanbornton, NH