1)  copy/paste the editor executable into it's own folder 

2)  rename "notepad.exe"

3)  copy

4)  delete notepad in the "windows" dirrecory

5) paste your new "notepad.exe"

for some reason if you try to delete notepad and rename another file notepad windows will automatically put another notepad in the windows dirrectory.

i'm sure there are some consequences to this but who cares!  notepad can't handle large files.

j9k

OR...you can just change the program that Mach Launches when you click the 'Edit GCode' button  . Go to Config->General Configuration, top of second column. just set that to the editor of your choice.

If you really want control you can do some VB on a button script 
This will open the currentl file loaded in Mach with Notepad...but you can tell it any program you want

Private Sub Form_Load()
Dim dTaskID As Double, path As String, file As String
path = "C:\WINDOWS\notepad.exe"
fileToLoad = Filename
dTaskID = Shell(path + " " + fileToLoad, vbNormalFocus)
MsgBox ("Text loaded")
End
End Sub

Isn't that what the 'Edit G-code' button on the main screen already does? But then I guess folks may be using diffrent screens so your point is well taken...

  forsure the VB way is the long and slow way around doing what Art's already done in C++  , but it might help if you want to mix it up with other code

thanks jeff.....  i totally missed that

j9k