Allow searching on a Jira Rank

We need to be able to search for items between 2 ranks in Jira. So a Search Ttemplate of Numbet Range is needed so for example we can search for items w/a Rank between 300 and 700

BTW it is strange that when you create the Greenhooper Rank custom field, it has a Serach Template of 'Number Searcher' but it seems to do nothing.