FrmMain.richtextbox1 = str + vbCrLf + richtextbox1

Public Function SaveFile(IntDir As String, Ext As String) As String
Dim FileName As String

On Error Resume Next
With FrmMain.DlgOpen
    .CancelError = False
    .DefaultExt = Ext
    .Filter = "." + Ext
    .DialogTitle = "Select file..."
    If IntDir <> "" Then
        .InitDir = IntDir
    Else
        .InitDir = ("c:\")
    End If
    .FileName = FileName
    .ShowSave
SaveFile = .FileName

End With
End Function

Public Function ExistFile(ByVal strFileName As String) As Boolean
ExistFile = False
On Error GoTo ExistFile_Err

If strFileName = "" Then Exit Function
If Dir(strFileName) <> "" Then
    ExistFile = True
Else
    ExistFile = False
End If
Exit Function

ExistFile_Err:
    //что то тут делаешь
End Function

Public Function my_Save(file_path As String)
Dim WordList_File As Integer

WordList_File = FreeFile
Open (file_path) For Output As WordList_File
            Print #WordList_File, FrmMain.richtextbox1
Close WordList_File
WordList_File = 0
End Function