Going forward you can refer this link below if it satisfies your requirement-
1.First we are creating a report with a dimension and two measure columns in which we will hide one of the column
If we are using pivot table
And border as 'Custom' and check the three layers and give the color as '#CCCCCC" as shown
And check the result
change the 'Custom' to '#CCCCCC'
in the second column to 100.So that it looks like its in the middle.