How do I find the row number containing the minimum value in column 0?

The following series of formulas can be used to find the row number containing the minimum value (or the first occurrence of the min. value) in column 0. The row number is stored in memory register m2.

m2=0;
m1=cmin(c0);
m2=(c0==m1 && m2==0) ? index() : m2;