Add this code to a command button or popup menu item.

VB Code:
  1. Dim objWord As Object
  2.     Dim objDoc  As Object
  3.     Dim strResult As String
  4.    
  5.     'Create a new instance of word Application
  6.     Set objWord = CreateObject("word.Application")
  7.  
  8.     Select Case objWord.Version
  9.         'Office 2000
  10.         Case "9.0"
  11.             Set objDoc = objWord.Documents.Add(, , 1, True)
  12.         'Office XP
  13.         Case "10.0"
  14.             Set objDoc = objWord.Documents.Add(, , 1, True)
  15.         'Office 97
  16.         Case Else ' Office 97
  17.             Set objDoc = objWord.Documents.Add
  18.     End Select
  19.  
  20.     objDoc.Content = Text1.Text
  21.     objDoc.CheckSpelling
  22.  
  23.     strResult = Left(objDoc.Content, Len(objDoc.Content) - 1)
  24.  
  25.     If Text1.Text = strResult Then
  26.         ' There were no spelling errors, so give the user a
  27.         ' visual signal that something happened
  28.         MsgBox "The spelling check is complete.", vbInformation + vbOKOnly
  29.     End If
  30.    
  31.     'Clean up
  32.     objDoc.Close False
  33.     Set objDoc = Nothing
  34.     objWord.Application.Quit True
  35.     Set objWord = Nothing
  36.  
  37.     ' Replace the selected text with the corrected text. It's important that
  38.     ' this be done after the "Clean Up" because otherwise there are problems
  39.     ' with the screen not repainting
  40.     Text1.Text = strResult
  41.  
  42.     Exit Sub