Good Day,
Sorry for replying so late. The following VBA code can help you solve the problem.

Private Sub UserForm_Initialize()
Dim xWSs As Worksheets
Dim xWS As Worksheet
Dim xName As String
Dim xI As Integer
Dim xRg As Range
On Error Resume Next

xName = "StoreWorkSheetsName"

Application.DisplayAlerts = False

If Not Evaluate("=ISREF('" & xName & "'!A1)") Then
Sheets.Add(after:=Worksheets(Worksheets.count)).Name = xName & ""
Else
Sheets(xName & "").Move after:=Worksheets(Worksheets.count)
End If
Set xWS = Sheets(xName & "")

For xI = 1 To Sheets.count - 1
xWS.Range("A" & xI).Value2 = Sheets(xI).Name
Next xI
xI = xI - 1
Set xRg = xWS.Range("A1:A" & xI)
ActiveWorkbook.Worksheets(xName).Sort.SortFields.Clear
ActiveWorkbook.Worksheets(xName).Sort.SortFields.Add Key:= _
Range("A1:A" & xI), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
xlSortNormal
With ActiveWorkbook.Worksheets(xName).Sort
.SetRange Range("A1:A" & xI)
.Header = xlGuess
.MatchCase = False
.Orientation = xlTopToBottom
.SortMethod = xlPinYin
.Apply
End With

Me.ComboBox1.Clear
For i = 1 To xRg.count
Me.ComboBox1.AddItem xRg.Item(i).Value

Next
Me.ComboBox1.Value = ActiveSheet.Name

xWS.Delete
Application.DisplayAlerts = True
End Sub