Here's a tricky one:

I would like an action to occur each time text is entered into a cell
in Column A. This needs to be done using VB, not a macro. When data is
entered into, say, cell A2, I would like the formulas in cells C2:E2
to be copied down into cells C3:E3.

The purpose of this is to avoid having formulas in cells until they
are needed (i.e. each time a row with formulas is used, a new blank
row with formulas is created).

In doing a web search for a solution, I found the following code
(props to Gord Dibben, circa 2003):

Copy/paste this Event code to your worksheet module.
Select Sheet TabView Code.
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
'when entering data in a cell in Col B
On Error GoTo enditall
If Target.Cells.Column = 2 Then
n = Target.Row
If Excel.Range("B" & n).Value < "" Then
Excel.Range("C" & n).Value = Excel.Range("B" & n).Value
End If
End If
enditall:
End Sub

Unfortunately, I am unable to adapt this to my specific
needs...anybody care to take a swing?