Hi, Andy...

Use BINTOC(). I've run into the same issue, and BINTOC does the trick.

So you'd have INDEX ON BINTOC(IntKey1) + BINTOC(IntKey2) TAG Whatever

(And obviously, any seeks into this tag would have to be something like

IF SEEK(BINTOC(m.IntKey1) + BINTOC(m.IntKey2),'Table','Tag')
...

Hope this helps.
Kevin