Thanks, Agathon, you seemed to have uncovered the mystery of this individual (the Quintin tome is superb)!
It is a murky case.
The column commander is repeatedly called a "general" in various references and there was only one during this era: Louis, comte Lemoine (Six, vol. II, p. 105). It seemed possible (though odd) that he might have been detailed to this task prior to taking up his appointment as cmdt of Wesel (Six does not always get the details right). But checking his LdH file (43 pages!) in Base Leonore, he was writing about receiving the honor on 15 May 1809 from Wesel so seems unlikely he was in the Tyrol in mid–April (not impossible, just very unlikely).
Odd as well, however, that a major would be assigned to conduct more than 2,000 conscripts north to Germany from Italy, especially as his regt (15e Chasseurs) was not one of those in these march columns. Not impossible, just odd.
Thanks again!