I have this AutoIt script:
ControlFocus(\"Open\", \"\", \"Edit1\")
Sleep(500)
ControlSetText(\"Open\", \"\", \"Edit1\", $CmdLine[1])
Sleep(500)
ControlClick(\"Op
Autoit uses pairs quotes to indicate a single instance within a string.
E.g., """"
(notice, there are 4 double quotation marks) acts as a single double-quote within the string.
So $CmdLine[1] & """"
should add a single double-quote.
See AutoIt's documentation. https://www.autoitscript.com/autoit3/docs/intro/lang_datatypes.htm has a section on strings.