at a second look, the bit I missed is that you never said the footswitch was midi. If it`s not then I suppose you`d have to get the H9 to generate a midi command triggered by a non midi response. I`m not entirely sure it has the means. 

If it`s a huge deal for you, you could pick up another simple three button midi footswitch and program it the same, then (I can only surmise) it could pass the same midi command to the next H9. Might take a little bit of tinkering but I don`t see it being difficult.