Código:
Private Sub Form_Load()
Dim LaReemplazada As String
Open "c:\de.txt" For Input As #1
Dim todo As String
todo = Input(LOF(1), #1)
Close #1
LaReemplazada = Replace(todo, " ", "")
Open "c:\de.txt" For Output As #1
Print #1, LaReemplazada
Close #1
End Sub
saludos.