Michael; I located the following information for you. My reference is to be found in Whitney's "The Black Hawk War 1831-1832.
You are correct, Your ancestor was in Ashtons Co, the most solid reference that I find (at this time), is that Ashtons company was under the command of Joseph Orr in July of 1832 at a place called Hickery Creek (location?) and that Ashton had been assigned to take a scouting party to Door Prarie Indiana, whether your ancestor was in this scouting party would be hard to determine. Though on July 19th of 1832, Orr send a highly detailed message to Genl Winfield Scott telling him of the findings of Ashton's expedition into this territory (ref Whitneys Vol II letters and papers pg# 828).