Sgt.
The best way to get the information you seek is to obtain the microfilm containing the compiled service records of the 18th Ky. Infantry. Several Ky. Libraries have it. I believe it can be rented from the National archives. It will require you to view the records of all the men in the regiment. It will take a lot of time but will yield the most accurate results. It could take 4 hours per roll and there are probably 5 or 6 rolls. You might see if your local library can get the microfilm through interlibrary loan.If you get it via National Archives or other source you can take it to a library and view it there. I have done this for six Ky. regiments but not the 18th.
Joe