VBA: Labeling a scatter plot with Slicers - implementation

[yk2vba]

Please help me to fix the error in my code! I'm trying to create a macro to label the points on my scatter plot with a slicer. The chart is an object on the worksheet with its source table. My data is Company (supposed to be a label), product (used as a slicer for the chart, allows only one product per chart), X and Y. I searched for the similar questions and found the solution for the case when the labels are in the known range. But in my case I have tons of Products and each product has its own number of companies, so it's a dynamic list of companies. What i'm trying to do in my solution is:

1. Identify the range of rows that correspond to a selected slicer (Product) - last row and total number of rows.
2. After calling Ch.GetChartElement x, y, idNum, a, b - I assume that b is a cell corresponding to XY point within the selected Product. So my thinking is: to find the first row of the range (last row-total rows) and after adding b to it, it will get the correct row number in column A (label).

This is my data and chart:

I was able to get the macro code to work partially, but it crashes after clicking on more than one point on the chart.
Here is my code in Class Module:

' ** Class module named Class1 **

Public WithEvents Ch As Chart

Dim idNum As Long
Dim a As Long
Dim b As Long

Private Sub Ch_MouseDown(ByVal Button As Long, ByVal Shift As Long, ByVal x As Long, ByVal y As Long)
Dim Txt As String
Txt = ""
Dim TotalRows As Long
Dim LastRow As Long
Dim r As Range

LastRow = Sheets("table_chart").Cells.SpecialCells(xlCellTypeLastCell).Row
TotalRows = Sheets("table_chart").Range("A1:A" &LastRow).SpecialCells(xlCellTypeVisible).Rows.Count
MsgBox TotalRows

Ch.GetChartElement x, y, idNum, a, b

If idNum = xlSeries Then
With ActiveChart.SeriesCollection(a).Points(b)
.HasDataLabel = True

'The goal of Txt string - for each XY on a chart find a Company Name in Column A.
' Sheets("table_chart") points to a tab with a table
' Range("A2:A" & Cells(Rows.Count, "A").End(xlUp).Row).SpecialCells(xlCellTypeVisible) is to find the Column A Range based on Product selection in Slicer
' Cells(LastRow - TotalRows - 1 + b, 1) to find the Company that corresponds to clicked XY point on the chart

Txt = Sheets("table_chart").Range("A2:A" & Cells(Rows.Count,"A").End(xlUp).Row).SpecialCells(xlCellTypeVisible).Cells(LastRow - TotalRows - 1 + b, 1).Value

With .DataLabel
.Text = Txt
.Position = xlLabelPositionAbove
.Font.Size = 8
.Border.Weight = xlHairline
.Border.LineStyle = xlAutomatic
.Interior.ColorIndex = 19
End With
End With
End If
End Sub

Private Sub Ch_MouseMove(ByVal Button As Long, ByVal Shift As Long, ByVal x As Long, ByVal y As Long)
' clear old marker
On Error Resume Next
Ch.SeriesCollection(a).Points(b).HasDataLabel = False
End Sub

Private Sub Ch_BeforeRightClick(Cancel As Boolean)
Cancel = True
End Sub
Private Sub Ch_BeforeDoubleClick(ByVal ElementID As Long, ByVal Arg1 As Long, ByVal Arg2 As Long, Cancel As Boolean)
Cancel = True
End Sub