Got this code that needs modifying ,can you help?

What goes here?
If Target.Column = 12 Then
ActiveSheet.ShowDataForm
End If
End Sub
Where to put it, and how do you specify what columns you want to use and
where the data goes. I may not be using the right form. I like Excels form
because you can keep entering data and it will put it in the right columns
as you enter it in a spreadsheet if you select forms from the menubar in
excel not VBA. Is there another type of form that you can use that you can
get it to popup when a specific cell is selected and have predefined headers
and have the data entered to be put it a specific place. What I am trying to
do is ,I have got a range of cells from L10 to L160 that I hope to use as
the trigger(selecting the cell and pressing enter), when L10 is selected
Hopefully this popup will popup and have 3 different Headers(associated with
3 different columns) with data fields, now there might be 1 or 30 entries
per header and it needs to be able to accommodate that.
Thanks<
Still Learning
David