choose the specific variable in r

There are data like this table.

v1 v2 v3 v4 v5 v6 v7 v8 v9 v10 v11 v12 v13 v14 v15

4  0  0  2  0  0  0  0  0   0   0   0   0   0   0

1  0  0  1  0  0  0  0  0   0   0   0   0   0   0

2  0  0  1  0  0  0  0  0   0   0   0   0   0   0

1  0  0  1  0  0  0  0  0   0   0   0   0   0   0

2  0  0  3  0  0  0  0  0   0   0   0   0   0   0

and I wish to make new matrix with the specific variable column which have the numerical value not zero(in this case the specific variable colum are v1 and v4)

I know the subset function but I cannot find the way to choose conditional columns by using "if statement".

I mean.. how can I make the matrix with the only specific columns that have numerical number by using "if statement"?

Please help me to solve my problem.