Public Function GenerateSQLSearchString(Columns() As String, Words() As String, _
  AlleWorterVorkommen As Boolean) As String
    Dim sqlString As String
    Dim i As Long, j As Long
    For i = 0 To UBound(Words)
        If Len(Words(i)) > 0 Then 'Wenn das Wort leer ist, keinen Ausdruck 
        ' angeben
            If i > 0 Then sqlString = sqlString & _
                IIf(AlleWorterVorkommen, " AND ", " OR ")
            sqlString = sqlString & "("
            For j = 0 To UBound(Columns)
                If j > 0 Then sqlString = sqlString & " OR "
                sqlString = sqlString & Columns(j) & " LIKE '%" + Words(i) + _
                  "%'"
            Next
            sqlString = sqlString & ")"
        End If
    Next
    GenerateSQLSearchString = sqlString
End Function

Dim Spalten() As String
ReDim Spalten(2)
Spalten(0) = "Spalte1"
Spalten(1) = "Spalte2"
Spalten(2) = "Spalte3"
 
Dim Suchstring As String
Suchstring = "Wort1 Wort2"
Dim Woerter() As String
Woerter = Split(Suchstring, " ") 'Suchstring über Leerzeichen in String-Array 
' splitten
MsgBox GenerateSQLSearchString(Spalten, Woerter, False)