To add own utilities on the XIDE Tools menu, you need to edit the Config\Toys.cfg file in your XIDE folder.

This a sample of such a configuration:

MENUENTRY=Windows API help file
EXECUTE=C:\cavo28\Help\win32sdk.chm

SEPARATOR

MENUENTRY=Vulcan At Warp Speed
EXECUTE=C:\Program Files (x86)\Vulcan.NET 4.0\Doc\Vulcan.NETAtWarpSpeed.pdf

MENUENTRY=ADS Help
EXECUTE=C:\CAVOTOOL\advantage.chm

MENUENTRY=VO-xPorter
EXECUTE=C:\XSharp\Compiler\VOXPorter\VOXporter.exe

Another possibility is to edit the XIDE.cfg file in your main XIDE folder, and add entries in the [FileTools] section. If this section does not exist, add it.

[FileTools]
xml = notepad.exe
txt = wordpad.exe,%1

The 2nd syntax allows you to use command line options, for example

wordpad.exe , /param1 %1 /param2

(%1 is replaced with the filename)

If you press CTRL or SHIFT while opening a file, it gets opened inside XIDE, instead of the tool you specified.