I require assistance with showing a value within the active cell.
It is intended for a internal company survey, where ratings are given
against adjacent questions.

For example, there are 5 questions, 5 possible ratings.
Columns B,C,D,E,F represent a number from 1 to 5, where B=5, C=4, D=3,
E=2 and F=1.
If Question1(Q1) deserves a 4 rating, then click on cell C1. So, cell
C1 would then show 4 in that cell.

A B C D E F
Q1. 4
Q2. 3
Q3. 5
Q4. 2
Q5. 4

The user will work down the rows from top to bottom, clicking on a
particular column to apply the appropriate rating.

Also, i want only ONE cell per row to be selected, so if user first
chose rating 3, but then wishes to change it to rating 2, i want the
rating 3 to disappear, and show only the new selected rating 2.

Can anybody help with this issue?

Thanks in advance.