Steam auto groupchat joiner..
Shortcut solution. (read below how to get the groupchat id for another group
First locate your steam folder. e.g "E:\Program Files (x86)\Steam"
Now right click on steam.exe > create a shortcut, click the new shortcut and go to properties.
You should see a tab called "target" which probably looks somewhat like this "E:\Program Files (x86)Steam\Steam.exe"
All you have to do now is simply add this command behind the target line which is "steam://friends/joinchat/103582791429537234"
Keep in mind that your target ends up looking like this "E:\Program Files (x86)Steam\Steam.exe" steam://friends/joinchat/103582791429537234
It is important that it looks like this or you will get errors. Of course E:\Program Files (x86)\Steam\Steam.exe should point to your own location of the steam exe. Just don't mess up the " char.
Click the shortcut to boot steam and enter the groupchat, alternatively you can click the shortcut while steam is already running and it will join the groupchat.
Join groupchat on windows start
To enter groupchat when you boot windows simply throw the above shortcut in your.
"C:\Users\yourusername\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup" folder and it will boot steam and join the groupchat for you.
Might want to disable "boot steam on start-up" in steam itself but doesn't really matter.
How to find my groupchat id?
If you want to apply the same concept for another groupchat the same rules apply. Just be sure to get the groupchat id from the community page > groups > select the *users* in Group Chat > right mouse and copy link.
Under chrome you might need to do right click > show page source and then search for "joinchat"
You should find something akin to <div class="joinchat_bg"
onclick="window.location='steam://friends/joinchat/103582791429537234'">
The numbers behind joinchat/ is your groupchat id.
I hope this tutorial was helpful to you and if you got any questions shoot me up on steam.