If I ask for another text input routine, I give you guys permission to curse me out. .

I'm trying to accept chemical formula input. In this routine, the first letter prompted for should be only uppercase. The second should be only lowercase (those are the only two allowed options). Pressing the down arrow key should allow you to type a subscript (there should be a designation in memory to indicate where the subscript starts and ends). Pressing the up arrow allows you to type superscript charges (2+, -1, ect.). Again, there should be a designation where the superscript starts and ends. You should be able to type parenthesis at any time. Can someone write such a routine for me? I'd even use the one out of the Balancer app, if I know who wrote it and have permission to use it.