Is there a way to modify this code with some 'autofill' in order to copy the
formula down that is located in Column C and D?

Sub test()
Dim InsertionPoint As Range, rg As Range
Dim colToCheck As String
Dim expandBy As Long
Dim wsh As Worksheet
Set wsh = ActiveSheet
colToCheck = "A"
expandBy = 25
'Find last currently used row in column colToCheck
Set InsertionPoint = wsh.Range(colToCheck & 65536).End(xlUp).Offset(1,
0).EntireRow

'Insert rows
Set rg = InsertionPoint.Resize(expandBy)
rg.Insert