The code below will handle the job for you. It is something I wrote for the big boss haha. I hope it helps. The code reads the first cell in the work sheet as the folder where docx files are present and then converts them to txt files one by one saving in the same folder.
Const wdFormatText = 2
If Not Len(Cells(1, "A").Value) > 0 Or Dir(Cells(1, "A").Value, vbDirectory) = "" Then
MsgBox ("Invalid Folder")
Exit Sub
End If
Dim StrFile As String
StrFile = Dir(Cells(1, "A").Value & "\*.docx")
Do While Len(StrFile) > 0
Set objWord = CreateObject("Word.Application")
Set objDoc = objWord.Documents.Open(Cells(1, "A").Value & "\" & StrFile, False, True)
objDoc.SaveAs Cells(1, "A").Value & "\" & StrFile & ".txt", wdFormatText
objWord.Quit
StrFile = Dir
Loop