Be sure that Minitab knows where to find your downloaded macro. Choose . Under Macro location browse to the location where you save macro files.
If you use an older web browser, when you click the Download button, the file may open in Quicktime, which shares the .mac file extension with Minitab macros. To save the macro, right-click the Download button and choose Save target as.
Suppose the matrix is in M1 and you want to store the determinant in K1. To run the macro, choose and type:
%MATRXDET M1 K1
Click Run.