touch /var/lib/sudo/$USER / use sudo when unlocking xscreensaver (xfce)

[Zenaan Harkness <zen@freedbms.net>]

I run sid XFCE, and have some keyboard shortcuts for
docked-with-external-monitor, no-external-monitor (.screenlayout
files) and corresponding networking configs.

In rc.local, I put touch /var/lib/sudo/{my-usr} and I find this very convenient.

I would like the same in principle, when unlocking xscreensaver.

Anyone know how to achieve this, or if it's possible without hacking some code?

TIA
Zenaan