Not clear what you are after?  Spaces will appear like a minus sign, while
text and numbers will appear like strikethrough.

I assume you don't want the spaces having a strikethrough.

A macro or event code can find the spaces and ignore them.

Macro..............

Sub strike_through()
'Strikethrough ignore spaces
Dim v As Variant, i As Integer
Dim cel As Range
For Each cel In Selection
   If cel.HasFormula = False Then
       v = cel.Value
           For i = 1 To Len(v)
           If Not (Mid(v, i, 1)) = Chr(32) Then
           cel.Characters(Start:=i, _
           Length:=1).Font.Strikethrough = True
           End If
       Next i
     End If
Next cel
End Sub

Gord Dibben  MS Excel MVP