He could use bold or bigger text just a suggestion.
Answer:
A. A1
Explanation:
Worksheet's Columns are named with Alphabets. i.e. A,B,C,D,E....
And Worksheet's rows are named with numbers. i.e. 1,2,3,4,5....
So the intersection of first row number as "1" and First Column name as "A" is A1 as worksheet displays column name first and then row number.
Are you trying to change the shape of an item within your program by entering the values into text boxes that become variables?
What language are you using?