It would have to be from what ever third party exporter you are using. C2 does not have access to a home folder, however you can:
A: Save the screenshot internally(webstorage, pretty limited)
B: Allow the user to download the screen shot(depends on the device)
C: Mail the screenshot(depends on the device)
D: Send the screenshot to a third party(php, cloud{dropbox,etc}, via ajax
Most of which will require the image be converted from base64 if you want to use the image in anything other than C2.