Thank you for your help. The book recommended from Hans-Karl Weiss proved very helpful after I had puzzled it out with the help of an online translation program. Your information has re-assured me that my translation turned out somewhat reliable.
My target, William Aylmer, is only mentioned once, when he was wounded and taken prisoner in 1809, but he was a junior officer, so this isn't surprising. Short of going to Vienna to seek his personnel file, that may be the best I can do. However, thanks to the gentlemen of the Napoleon Series, at least I know where his regiment fought, even if I can't be sure he was present.
Thanks again, John Brewster