Shift+CapsLock to toggle caps lock functionality
As Seil only affects the CapS Lock key itself, it's not going to be listening for anything other than that.

I'm sure it would be easier overall to restore the Caps Lock key &amp; just use Fn-Delete for forwards delete.

See http://support.apple.com/kb/HT1343?viewlocale=en_US&amp;locale=en_US for the full set of key commands.