I have a list of ~100 values in a column. I want to find all possible differences among cells of a value of 30 +/ 2. For example, 1200, 1201, 1205, 1208, 1230. The difference between values 1 and 5 and 2 and 5 would be found.

"Transpose the cells in the column into the top row, by paste special and paste value. Then subtract the absolute value and drag the formula until you reach the last column and row. =ABS($A2D$1) Then conditional formatting, highlight cell rules, between...28 and 32." (OP) 

