Sub znach()
Application.DisplayAlerts = False
    CalcMode = Application.Calculation
    RefStyle = Application.ReferenceStyle
    Application.Calculation = xlCalculationManual
    Application.ScreenUpdating = False

Dim c As Range, f$
On Error Resume Next
With ActiveSheet.UsedRange
Set c = .Find(What:="!", LookIn:=xlFormulas, _
LookAt:=xlPart, MatchCase:=False, SearchFormat:=False)
If Not c Is Nothing Then
f = c.Address
Do
c.Value = c.Value
Set c = .FindNext(c)
Loop While Not c Is Nothing And c.Address <> f
End If
End With

Application.DisplayAlerts = True
    Application.Calculation = CalcMode
    Application.ReferenceStyle = RefStyle
    Application.ScreenUpdating = True
End Sub

замените With ActiveSheet.UsedRange
на With Selection