Correlation Matrix:bunch of nested if statements

Hello,

I am trying to make a correlation matrix. Lets say you have columns of values from B to D. So you make a matrix with those values on the X and Y and have a 3x3. Obviously only the bottom triangle is relevant because the top with have the same values. Now is the best way to go about this to rename the columns of values and refer to them in the =COrrel(..) formula or to use a bunch of nested if statements based on the matrix cell headings. I appreciate any queries.
Thanks.