How to copy the value in a range of cells to another cell if only one cell in the range has a value?

Question

I have 40 columns and several hundred rows in an Excel spreadsheet.

Range C6:AQ6, C7:AQ7, C8:AQ8, and so on

CASE 1: Only one cell in the range D6:AQ6 usually contains a value. 
CASE 2: In some rare cases, more than one cell OR no cells contain a value in this range.

Here is what I want to accomplish:

If CASE 1: Populate the cell C6 with the value in the only cell in the range D6:AQ6.
If CASE 2: Leave C6 blank

How do I do this using Excel formulae?

Answer 1

Enter this formula into Cell C6:

=IF(COUNTA(D6:AQ6)=1,INDEX(D6:AQ6,Match("*",D6:AQ6,0)),"")

How it works:

• Count's how many Cells in the range "D6:AQ6" are not blank.
  • If there is only 1 cell with data (Case1)
    • Then use index to return the value
      • Index works by returning the value form the cell X to the right where X is the first column Match finds that has anything inside of it
  • If there is not 1 (more than 1 or 0, Case2)
    • then set the cell to blank