I do not believe those records are on line. The records are arranged in alphabetical order so at least one roll of the microfilm would have men's names that began with Ma. Whether it's possible to get that microfilm roll through interlibrary loan is something that you might explore. The National Archives and Records Administration (NARA) has a pretty good web site. You could contact the Old Army Records Branch in Washington, DC with your questions. Ultimately you might have to hire a researcher to visit the Archives in DC, or at a regional repository for the records.