Macro Merge Multiple Files Into One Worksheet

I have this macro to go to a specific folder and open up all of the files in the folder and merge them into a worksheet.
I want to change it so the user can select the files to be merged.

any suggestions?
thanks

Sub MergeFiles()
Dim path As String, ThisWB As String, lngFilecounter As Long
Dim wbDest As Workbook, shtDest As Worksheet, ws As Worksheet
Dim Filename As String, Wkb As Workbook
Dim CopyRng As Range, Dest As Range
Dim RowofCopySheet As Integer
RowofCopySheet = 2 ' Row to start on in the sheets you are copying from
ThisWB = ActiveWorkbook.Name

path = ("F:\Action O-I\Numeric Data Upload\Numeric Response Per Dept\Test")
Application.EnableEvents = False
Application.ScreenUpdating = False
Set shtDest = ActiveWorkbook.Sheets("Upload File")
Filename = Dir(path & "\*.xls", vbNormal)
If Len(Filename) = 0 Then Exit Sub
Do Until Filename = vbNullString
If Not Filename = ThisWB Then
Set Wkb = Workbooks.Open(Filename:=path & "\" & Filename)
Set CopyRng = Wkb.Sheets(1).Range(Cells(RowofCopySheet, 1), Cells(Cells(Rows.Count, 1).End(xlUp).Row, Cells(1, Columns.Count).End(xlToLeft).Column))
Set Dest = shtDest.Range("A" & shtDest.UsedRange.SpecialCells(xlCellTypeLastCell).Row + 1)
CopyRng.Copy
Sheets("Upload File").Select
Dest.PasteSpecial xlPasteValuesAndNumberFormats
Application.CutCopyMode = False 'Clear Clipboard
Wkb.Close False
End If

Filename = Dir()
Loop


Range("A1").Select

Application.EnableEvents = True
Application.ScreenUpdating = True

MsgBox "Done!"
End Sub