I do not know an Excel function that will do the job but
easiest way is to use some macro.
1. right click on the toolbar and select Control Tool Box
2. click on Command Button that looks like a rectangle in
the tool box then move to the worksheet and click anywhere
within the worksheet -- Command Button 1 will appear
3. double click on the Command Button--Project-VBA code
sheet will appear
4. between between Private Sub CommandButton1_Click() and
End Sub write the following code (if you want the result
in Cells(1,7) which is the same as Range("G1")):
Dim intRow As Integer
Dim intCol as Integer
intRow = 1
intCol=1 '1 is Column A, 5 is Column E, etc.
Do Until Cells(intRow, intCol) = ""
If Cells(intRow, intCol) > 0 Then
Cells(1, 7) = Cells(intRow, intCol)
Exit Sub
End If
intRow = intRow + 1
Loop
5. switch back to Excel and exit design mode by clicking
on a tool that looks like triangle and straight rulers and
a pencil
6. when you click on the command button, your result(the
first non-zero) will appear in G1 or cells(1,7)