10
Use the split command like this
Dim TempS As String
TempS = " This is a split test "
Dim V As Variant
V = Split(TempS, " ")
Cls
Print UBound(V) '7
V = Split(TempS, "i")
Print UBound(V) '3
V = Split(TempS, "e")
Print UBound(V) '1
You can combine it to a single line.
Print UBound(Split(TempS, "i"))
I did some crude timing on it. On a 40,000 character string with all spaces it seems to clock in at 17 milliseconds on a 2.4 GHz Intel Core 2 processor.
A function could look like this
Function CountChar(ByVal Text As String, ByVal Char As String) As Long
Dim V As Variant
V = Split(Text, Char)
CountChar = UBound(V)
End Function