Using PRIMARY clipboard in macOS
According to OSX Daily, there is an alternative clipboard with the Mac that will not overwrite the standard clipboard. The commands are Control-k, which does a cut on selected text (not copy) and Control-y which then pastes that data. The article is here: http://osxdaily.com/2012/02/01/use-a-secondary-cut-and-paste-function-to-avoid-overwriting-clipboard-contents/

The article also mentions a 3rd part app, ClipMenu which also might address your desires.