An example of you data would help, but

Sub ABC()
Dim rng As Range, cell As Range
Dim s As String, s1 As String
Dim sChr As String, i as Long
Set rng = Range(Cells(1, 1), Cells(Rows.Count, 1).End(xlUp))
For Each cell In rng
 s1 = ""
 s = cell.Text
 If Len(s) >= 4 Then
   For i = 1 To Len(s)
    sChr = Mid(s, i, 1)
    If sChr Like "[A-Za-z]" Then
       s1 = s1 & sChr
    End If
   If Len(s1) >= 4 Then
        Cells(cell.Row, "H").Value = s1
   End If
   Next
 End If
Next

End Sub

should work.  If you mean only cells that are completely text and the range
contains only cells that are completely numbers stored as numbers or text :

for example
Header1
123
456
689

Header3
234
567
891

Then it would be:

Sub AAAA()
Dim rng as Range, cella s Range
Set rng = Range(Cells(1, 1), Cells(Rows.Count,
1).End(xlUp)).SpecialCells(xlConstants,xlTextValues)
for each cell in rng
  cell.offset(0,7).Value = cell.Value
Next
End Sub