You could use a macro.
Select the range then run.
Sub RemoveAlphas()
Dim intI As Integer
Dim rngR As Range, rngRR As Range
Dim strNotNum As String, strTemp As String
Set rngRR = Selection.SpecialCells(xlCellTypeConstants, _
xlTextValues)
For Each rngR In rngRR
strTemp = ""
For intI = 1 To Len(rngR.Value)
If Not Mid(rngR.Value, intI, 1) Like "[A-Z,a-z]" Then
strNotNum = Mid(rngR.Value, intI, 1)
Else: strNotNum = ""
End If
strTemp = strTemp & strNotNum
Next intI
rngR.Value = strTemp
Next rngR
End Sub
Gord