vmstat graphing with CPU io wait

My old BB setup has a customized vmstat-larrd.pl script which allows for variations in vmstat output based on the version of procps. In other words, it compensates for the fact that RHEL3 and old red hat linux systems have vmstat output who's column ordering doesn't match up.

So I'd like to bring some of those vmstat changes into my new hobbit setup, most notably the ability to plot CPU wait for IO (wa) alongside user, system & idle time, but poking around in hobbitgraph.cfg doesn't reveal an easy way to do it.

Any tips on how I might accomplish this?

Tom