You have a few choices. With your activetcl regular installation, then
you would just unzip it into your tcl's lib directory. Then a package
require would find it.
Or you could put it wherever you want and add the path to the ::auto_path
global variable.
Or if you want a single file tclkit with twapi built in, check out,
https://sourceforge.net/projects/twapi/files/Tcl binaries/Tclkits with TWAPI/