I would like to add another command to "Save as" menu that is generated by right clicking on selected text.

[![enter image description here][1]][1]

We have there "Plain Text" and after this I would like to add "Sagemath code".
After clicking on it the text/code would be copied as plaintext with addition that spaces that represent multiplication would be replaced with "*".

For example if you "copy as plain text" this code `3 x^2 + 2 x + 1` you get string "3 x^2 + 2 x + 1" but I would like it to be `3*x^2 + 2*x + 1` because Sagemath recognizes only "*" as multiplication.

Sorry no code from me. I have no clues how to do it.


**Update:**

Why the code from [here][2] does not work anymore?

The code should rewrite the file `MenuSetup.tr` with new menu (in my code with unchanged default menu) but when I look at the file its modification time is not changed which means nothing was done to the file `Wolfram Research\Mathematica\8.0\SystemFiles\FrontEnd\TextResources\Windows\MenuSetup.tr`.

    Begin["System`"];
    menu = Get[
       FileNameJoin[{$InstallationDirectory, "SystemFiles", "FrontEnd", 
         "TextResources", "Windows", "MenuSetup.tr"}]];
    End[];
    FrontEndExecute[FrontEnd`ResetMenusPacket[menu]]


  [1]: https://i.sstatic.net/fgnzU.png
  [2]: https://mathematica.stackexchange.com/a/1409/53172