Msg error (overflow)

hey,

I don't know what's the cause of that error in the below code :

Dim cell, rng As Range
Dim nRow As Integer
Sheet7.Select
Me.Height = 390
nRow = Sheet7.Cells(7, 3).End(xlDown).Row
With Autofilter.lstTable
    .Clear
    .ColumnCount = 16
    .ColumnWidths = "50;120;60;60;100;35;35;60;70;60;50;20;40;55;55;70"
    .ColumnHeads = True
    .RowSource = Sheet7.Range(Cells(7, 3), Cells(nRow, 32)).Address
End With

The error msg (overflow) in that part:

nRow = Sheet7.Cells(7, 3).End(xlDown).Row

second; I have 16 columns should appear in listBox (lstTable), and i want 2 know If I have a column has a special format in sheet eg. (font:Wingdings 2), How can I format that column in listbox ???

THX...