Sometime around last year I was able to add a shortcut I made on the desktop that would open up Power Shell and go to a different default directory that I picked. Since then I've reformatted windows and reinstalled everything. Now every time I either manually add the Power Shell or add the link it defaults to the Power Shell directory.

Is there any way to make a shortcut that defaults to whatever "Start In" directory I want? I've attached a screenshot of the options I get when I edit the shortcut.

I tried adding the directory "D:\blah blah\" to command line arguments and cd "D:\blah blah\" and it errors out and closes.

If you unprotect your attachment others may be able to help you, assuming there is nothing sensitive in the attachment that is.

Done. Didn't even know that was possible since when I uploaded just said you and mods only.

Does this help?
https://www.displayfusion.com/Discussions/View/customizing-the-displayfusion-taskbar/?ID=9d11f8e8-1cdb-4c5e-8a08-110531ee21d3

I would have posted a couple of screenshots showing the Pin to taskbar but my system is in Swedish which I am guessing of no use to you

The images from that are from 5.1.1 and I'm on 9.2.2 the image I posted above is what I get on "Edit Taskbar Shortcuts" and is drastically different than the one on the page you linked.

Even then I don't see how I can define the "Start In" area.

I am sorry if I am not understanding you properly. I thought you wanted a taskbar shortcut to open a file or folder. If this is correct then all you need do is open the file or folder on the screen that you want to pin the shortcut. Right click on the icon on the tasbar and you will see Pin To This Taskbar, click on that.
As I said if thats not what you meant then I apologise.

If you meant that you wanted to pin PowerShell to the taskbar and make it open at a dedicated folder rather than system32 then add this to the Command Line Arguments box.
-noexit -command cd C:\Windows
just change the c:\windows to the folder you want powershell to start in.