scripting screenshot of fixed selection to clipboard

[IIO]

say i needed to make a screenshot from the application ABC limited to e.g. 300 300 800 800 relative to the left top screen corner, and save that screenshot ONLY in the OS clipboard (i.e. without writing a file to disk before)

in an ideal case you would just lauch a script from the applemenu to do so.

(in OSX i also had access to the tcsh shell from within maxmsp.)

is that possible? any ideas?

i needed it for OS9, OSX PPC, later OSX, win10

[robespierre]

Seems like it is possible using screencapture, mktemp, and ImageMagick's convert.