Welcome to VBAX isabelle r. Perhaps this will get you started
Public Function PropCaps(varLastName) As Variant
    'Purpose  : Proper capitalization of names with more than one Cap such as D'Angelo, O'Brein, McDonald.
    'Note: does not attempt names like MacDoogal. Too many exceptions with names starting with Mac.
    'DateTime : 5/05/2000
    'Author   : Bill Mosca
    Dim varOut As Variant
    Dim intPos As Integer
    If IsNull(varLastName) Then Exit Function
    'Irish
    intPos = InStr(1, varLastName, "MC", vbTextCompare)
    If intPos > 0 Then
        varOut = StrConv(Left(varLastName, 2), vbProperCase) _
            & StrConv(Mid(varLastName, 3), vbProperCase)
    End If
    'Various ancestry.
    intPos = InStr(varLastName, "'")
    If intPos > 0 Then
        varOut = StrConv(Left(varLastName, intPos), vbProperCase) _
            & StrConv(Mid(varLastName, intPos + 1), vbProperCase)
    End If
    PropCaps = varOut
End Function