timmy2

Insightful comment, TheSaint.  I had tried using the Handle identifier with Zoom Player but couldn't get it to work reliably (though in retrospect this could've been SystemInfo (which the author says is written in Delphi).
Perhaps you can help explain the results of the following test code I wrote in reaction to your comments above.
Opt("WinTitleMatchMode", 1) $handle = WinGetHandle("Zoom Player") If @error Then MsgBox(4096, "Error", "Could not find the correct window") MsgBox(1,"","The handle is: " & String($handle)) $handle2 = WinMove("[CLASS:TMainForm]","",0,0) If @error Then MsgBox(4096, "Error", "Could not find the correct window") MsgBox(1,"","The handle is: " & String($handle2) & " or is it: " & string($handle)) WinMove($handle2,"",1600,1060) If @error Then MsgBox(4096, "Error", "Could not find the correct window") No errors are generated.  And the video window moves as each WinMove function instructs. The first MsgBox that shows the $handle from WinGetHandle says the handle is 0x004002D6. The second MsgBox that compares $handle with $handle2 says: "The handle is: 0x00070CDE or is it: 0x004002D6"
According to Au3Info the 070CDE value is the correct Handle.  The fact that I had been using WinGetHandle to get the handle value explains why subsequent uses of it failed to work. So what's another way for me to have gotten the handle before I tried a WinMove?
And, incidentally, I tried this code with SystemInfo running and not running. My script moved the video window twice when SystemInfo was not running; my script could not move the window in either instance of WinMove when SystemInfo was running, which suggests to me that regardless of having the handle as an identifier, SystemInfo is doing something else to impact my script.
Thank you VERY much for your help!