You would need to use a User-Defined-Function - see code below.

Used like

=myMax(A1)

HTH,
Bernie
MS Excel MVP


Function myMax(incell As Range) As Double
Dim myArr As Variant
Dim myDbl() As Double
Dim i As Integer
myArr = Split(incell.Value, ",")
ReDim myDbl(LBound(myArr) To UBound(myArr))
For i = LBound(myArr) To UBound(myArr)
myDbl(i) = CDbl(myArr(i))
Next i
myMax = Application.Max(myDbl)
End Function


"Hells" wrote in message
...
Hello,

Can anyone help me, I wish to return the higest number in a string of
numbers (all in the same cell) seperated by commas.

Thanks