Placement of Help button: left or right to OK/Cancel

I'm adding help to a Windows desktop application that is being in use since the Windows XP era. All the modal dialogs display the typical OK/Cancel button set placed at the bottom right as shown in this example dialog:

Layout OK Cancel (Help is not present)

I wish to cause minimal confusion to my users after the next release that's why I hesitate to place the Help button right to the Cancel button. The (seemingly) standardized order shown by the Win32 MessageBox function (with MB_OKCANCEL | MB_HELP combined) would shift the already existing buttons to right (replacing OK by Cancel and Cancel by Help) like this:

Layout OK Cancel Help

I searched the web for this issue, but it turned out to be very hard to get useful answers when combining help, button, and placement, nevertheless I found some screenshots with help buttons bottom left which looks good and useful from my POV.

Where should I place the Help button to the dialogs of an old-fashioned application?

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