GOT IT DONE!
Here's what I finally learned...
Use the Function: Execute Basic-Script, F-code: 34, Execute code: HtmlDialog( GetMainFolder()+"Mach3MillGcode.htm" ), HtmlDialog( GetMainFolder()+"Mach3MillGcodeLetters.htm" ),
and HtmlDialog( GetMainFolder()+"Mach3MillMcode.htm" ) respectively, for each button (G-Codes, G-Code Letters, M-Codes).
I also converted and renamed the .bmp files in the C:\Mach3\Bitmaps\MillBitmaps\ folder for each of those bitmaps (G-codes_US.bmp, G-code-letters_US.bmp; M-codes_US.bmp) to .htm files and put them in the main Mach3 folder.
Now the buttons pull up their respective lists and place them on top of the screen for reference.
Thanks again for the assistance!!
Bob