Current cell - CORROW, CURCOL equivalents

[roaftech]

Prior to being forceably converted to Excel some 20 years ago, I was something of a guru with SuperCalc. I am looking for the Excel equivalents of CURCELL, CURROW and CURCOL, which return the current (ie Active in Excel) cell, row and column respectively.
The context is that I am preparing a data sheet which (inter alia) records the names of aid beneficiaries each month. Some beneficiaries appear only once per month; others more often. The names show in bold if the person has been before, and various other interesting notes appear, but this all relies on being able to recognise the contents of the active cell as data is being entered or when clicked retrospectively. In due course this info will be going into a database; this form is a way of capturing the data and weeding out some of the errors whilst it is still relatively recent.

Searching through the forum I have come upon a thread dating from 2005 which includes some VBA code:

 ...
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Column = 1 And Target.Row >= 1 And Target.Row <= 20 Then
Range("C1") = ActiveCell.Value
End If
End Sub
  ...

which, once modified for my references, does the job very nicely.

However, from my point of view, it has three problems:
1) it negates the undo button (very important to us);
2) it is not dynamic, in that if we add extra rows into the data area the code doesn't adjust to them;
3) it's a macro, which has security implications (the files won't load on the normal Excel installation).

Any ideas for a better way of doing things?