bRecursive = False
sFolder = "C:\Users\curio\Desktop\rough\rtf_combine"
Set oFSO = CreateObject("Scripting.FileSystemObject")
Set oWord = CreateObject("Word.Application")
oWord.Visible = True

Set oFolder = oFSO.GetFolder(sFolder)
ConvertFolder(oFolder)
oWord.Quit

Sub ConvertFolder(oFldr)
  For Each oFile In oFldr.Files
    If LCase(oFSO.GetExtensionName(oFile.Name)) = "rtf" Then
        Set oDoc = oWord.Documents.Open(oFile.path)
        Str = left(oFile,instr(1,oFile,".")-1) 
        oWord.ActiveDocument.SaveAs Str & ".pdf", 17
        oDoc.Close
    End If
Next

If bRecursive Then
    For Each oSubfolder In oFldr.Subfolders
        ConvertFolder oSubfolder
    Next
End If
End Sub