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

Bob
This is the right form, I dont think I am wording what I want to do right,
so if you would please be patient

What it needs to do when L10 is selected is to popup a form which it does
,BUT I need to specify what and where the headers are along with where the
data field are

Sorry for not saying that earlier

If L10 is selected it needs to go to A500-C500 to look at the headers and
the data would need to go in A501-C549 only, then if you move to L11 it
would advance down 50 lines,
example
If L11 is selected it needs to go to A550-C550 to look at the headers and
the data would need to go in A551-C600 only and so on.
Sorry for the confusion on the name of the code, but it wasnt downloaded
with the code