You can use a For Each to iterate through all the cells in a defined range.
Public Sub IterateThroughRange()
Dim wb As Workbook
Dim ws As Worksheet
Dim rng As Range
Dim cell As Range
Set wb = Application.Workbooks(1)
Set ws = wb.Sheets(1)
Set rng = ws.Range("A1", "C3")
For Each cell In rng.Cells
cell.Value = cell.Address
Next cell
End Sub