The following macro will achieve what you need. It uses column A for the data. If your column is not 'A', you will need to modify the code as follows:
Line 3: Change "A" to your column letter, i.e. "C"
Line 5: Change "A1:A" to your column letter, i.e. "C1:C"
Line 19: Change "A1" to your column letter, i.e. "C1"
Open the workbook
Copy this macro, modified if necessary, to the clipboard:
Sub StripCells()
Dim i, newVal, rng As Range
LastRow = Range("A" & Rows.Count).End(xlUp).Row
Application.ScreenUpdating = False
Set rng = Range("A1:A" & LastRow)
For Each cell In rng
cell.Select
For i = 1 To Len(ActiveCell)
If Asc(Mid(ActiveCell, i, 1)) > 65 _
And Asc(Mid(ActiveCell, i, 1)) < 91 _
Or Asc(Mid(ActiveCell, i, 1)) > 96 _
And Asc(Mid(ActiveCell, i, 1)) < 123 Then
newVal = newVal & Mid(ActiveCell, i, 1)
End If
Next i
ActiveCell.Value = newVal
newVal = ""
Next
Range("A1").Select
End Sub
Press ALT + F11
INSERT > MODULE
Paste the macro into the module editing area to the right.
Close back to Excel.
Go to Tools > Macro > Macros
Highlight this macro, if not already highlighted.
Click 'Options..' (bottom right)
Select a letter to be used as a keyboard shortcut.
Close back to Excel.
Press CTRL + your letter to run the macro.