One list of names:
names = c(col1, col2, col6)
matrix like this:
col1 col2 col3 col4 col5 col6
1 4 5 2 7 2
4 5 7 2 8 1
in order to have this:
col1 col2 col6
1 4 2
4 5 1
select "names" from "matrix" to create a new matrix.