Automatic write diagram's titles in Excel VBA - excel

Question

I try to add in a given script some commands in order to automatically update the titles of charts (the charts are produced from the same script provided by Scott Holtzman).
My questions:
1. How can I escape quotes in order to update the text with given variables (I have read this can be done with double quotes ""i"" but it is not working)
2. It is possible to write greek characters and how?
3. It is possible to write with indices or lower case letters or subscripts?
4. How can I change the axes labels? I have defined two but I am changing only the y-axis and not the x-axis.
Here is my script (provided by Scott Holtzman) and my comments waht I am trying to do:
Sub MakeCharts()
Dim ws As Worksheet
Set ws = Sheets("Tabelle1")
Dim dthArray() As Variant
Dim kxArray() As Variant
Dim text1 As String
Dim text2 As String
Dim x As Integer
Dim y As Integer
Dim i As Integer
Dim j As Integer
i = 1
j = 1
' Strings for the charts'titles:
dthArray() = Array("0", "0,5", "1", "5", "10")
kxArray() = Array("0", "0,01", "1", "5")
For y = 1 To 259 Step 65
For x = 1 To 259 Step 13
ws.Shapes.AddChart.Select
With ActiveChart
.ChartType = xlXYScatterSmoothNoMarkers
Dim k As Integer
For k = 1 To 13
.SeriesCollection.NewSeries
.SeriesCollection(k).Name = ws.Cells(x, k + 1)
.SeriesCollection(k).XValues = ws.Range(ws.Cells(x + 1, k + 1), ws.Cells(x + 11, k + 1))
.SeriesCollection(k).Values = ws.Range(ws.Cells(x + 1, 1), ws.Cells(x + 11, 1))
.HasTitle = True
Next
.ApplyLayout (1)
Dim sName As String
sName = Replace(.Name, ws.Name & " ", "")
'Updating String for chart's title
text1 = dthArray(i)
text2 = kxArray(j)
' Write chart's title
.ChartTitle.Text = "dth=""text1""" & " " & "dx = ""text2"""
'sigma should be in greek and t as subscript
.Axes(xlValue, xlPrimary).AxisTitle.Text = "sigmat/a"
.Axes(xlValue, xlPrimary).AxisTitle.Text = "eta=y/H"
End With
With ActiveSheet.Shapes(sName)
.IncrementLeft 300
.IncrementTop x * 20
End With
i = i + 1
Next
j = j + 1
Next
End Sub
Any suggestions?