This post is just to bookmark the solution from the Stackoverflow link below, Mobaxterm is not in a standard installation path in the below example, please modify your code based on your circumstances.
Create a batch file with below content, then place it in a folder such as “C:\Program Files\EVE-NG”
@echo off
SET input=%1
FOR /f "tokens=1,2,3 delims=:" %%a IN ("%input%") do SET host=%%b&SET port=%%c
SET host=%host:~2%
echo %host%
echo %port%
cd C:\MobaXterm\
MobaXterm.exe -newtab "telnet -r %host% %port%:~0,-1%"
sleep 6
exit
Create a reg file, run it
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Classes\MobaXterm.telnet]
@="telnet"
[HKEY_CURRENT_USER\SOFTWARE\Classes\MobaXterm.telnet\DefaultIcon]
@="C:\\MobaXterm\\MobaXterm.exe, 0"
[HKEY_CURRENT_USER\SOFTWARE\Classes\MobaXterm.telnet\shell]
[HKEY_CURRENT_USER\SOFTWARE\Classes\MobaXterm.telnet\shell\open]
[HKEY_CURRENT_USER\SOFTWARE\Classes\MobaXterm.telnet\shell\open\command]
@="\"C:\\Program Files\\EVE-NG\\start_mobaxterm.bat\" %1"
[HKEY_CURRENT_USER\SOFTWARE\MobaXterm]
[HKEY_CURRENT_USER\SOFTWARE\MobaXterm\Capabilities]
[HKEY_CURRENT_USER\SOFTWARE\MobaXterm\Capabilities\URLAssociations]
"telnet"="MobaXterm.telnet"
[HKEY_CURRENT_USER\SOFTWARE\RegisteredApplications]
"MobaXterm"="Software\\MobaXterm\\Capabilities"
[HKEY_CURRENT_USER\SOFTWARE\Classes\telnet\shell]
[HKEY_CURRENT_USER\SOFTWARE\Classes\telnet\shell\open]
[HKEY_CURRENT_USER\SOFTWARE\Classes\telnet\shell\open\command]
@="\"C:\\Program Files\\EVE-NG\\start_mobaxterm.bat\" %1"
[Computer\HKEY_CLASSES_ROOT\telnet\shell\open\command]
@="\"C:\\Program Files\\EVE-NG\\start_mobaxterm.bat\" %1"
Reboot you computer
Then when you try to open the “telnet://” link, open with your “start_mobaxterm.bat”.