I'm building some complex sheets and to complete this task I need a formula
that finds "the number of the lowest row, of a column, witch is not empty".

For exemple, in Column A we have:

A1=   12.3
A2=   2.9
A3=   3.5
A4=             (is empty)
A5=   3
A6=   10.3
A7=             (is empty)
A8=             (is empty)
Ax=             (is empty)
.                         .
.                         .
(and so on)

Under A6, there is no filled cells in the column A.
I need a formula that returns "6", that is the number of the lowest row that
is not empty (A6=10.3).

PS:
I managed to get some good results adding formulas to a parallel column (B)
this way>

Column A                       Column B

A1=12.3                         B1=If(A1>0;Row();0)     (B1 returns 1)
A2=2.9                           B2=If(A2>0;Row();0)     (B2 returns 2)
A3=3.5                           B3=If(A3>0;Row();0)     (B3 returns 3)
A4=                                 B4=If(A4>0;Row();0)     (B4 returns 0)
A5=3                               B5=If(A5>0;Row();0)     (B5 returns 5)
A6=10.3                         B6=If(A6>0;Row();0)     (B6 returns 6)
A7=                                 B7=If(A7>0;Row();0)     (B7 returns 0)
A8=                                 B8=If(A8>0;Row();0)     (B8 returns 0)
.                .
.                .
.                .

And then the formula "Max(B:B)" returns the desired number (6).

But this way is not good enough because it needs a "parallel column" (column
B in my example) for EACH column I want to avaliate, and it would make my
sheet confusing for its users.

I need a solution so much... lol
Hope someone can help... lol

Roberto Villa Real