Sub szukaj()
Dim txtSzukanyTekst As String, intWynik As Integer, kom As Range

txtSzukanyTekst = "mleko"

For Each kom In Range("A1:A20")

intWynik = InStr(1, kom, txtSzukanyTekst, 1)

    If intWynik > 0 Then kom.Interior.Color = 255

Next kom
End Sub

Dim txtSzukanyTekst, txtZawartoscKomorki As String
Dim intWynik As Integer

txtSzukanyTekst = TextBox1.Value

Range("A1").Activate

For i = 0 To 20
txtZawartoscKomorki = ActiveCell.Value

intWynik = InStr(1, txtZawartoscKomorki, txtSzukanyTekst, 1)

    If intWynik > 0 Then
        With Selection.Interior
            .Color = 255
        End With
        ActiveCell.Offset(1, 0).Activate
    Else
        ActiveCell.Offset(1, 0).Activate
    End If

Next i