Thanks Balf. Yes, MinionPro was on my list to try out. Though, I did not know that it had all those additional features. It looks nice and professional, but since it is a little work to use it, I will have to wait for a couple of weeks when I have the time to try it out.
I tried using the method you suggested yesterday. With that, unfortunately, when I have two letters in a subscript; such as
, the second letter is a little smaller than the first one. I wonder why. Hence, I went with Juanjo suggestion and used
instead. That works pretty well for my case. Also, that way I can stick to the charter font.
Thanks again for your suggestions.