Question: Excel does not find Maple engine library maple.dll for Maple add-in

What is the solution to this error message when trying to run the Maple add-in for Excel?
"The specified module could not be found.  OpenMaple cannot find Maple engine library, maple.dll."

I am running Maple 19.1 and Excel 2016, both 32-bit, in Windows 7.  Excel appears to have successfully installed the Maple add-in.  For example, the Maple add-in icons appear on the Add-ins tab of Excel.  Excel shows the Maple add-in as active in the list of add-ins.  The location of he WMIMPLEX.xla is correct at "C:\Program Files (x86)\Maple\Excel\WMIMPLEX.xla.

Maple support tells me that Maple should add its "bin" folder to the PATH key for excel.exe in the registry key "Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\excel.exe\Path".  This path information, however, is not in my computer's registry.  This missing path information might be an obvious problem.  But what is the correct registry entry so that Excel knows where to find the Maple engine library maple.dll?

I tried adding the path to maple.dll in the environmental path variables of Windows 7, but that approach did not work.  I have uninstalled, rebooted, and reinstalled Maple 2019 (32-bit) several times.  Still the same error message.

Thanks.