Extend from within Trim Entities - What is the hotkey?

I am using SW2014 SP5.

I seem to recall that you could "extend" sketch entities from within the Trim Entities command by holding down a key (shift, ctrl, alt). Trim to nearest is not what I am after.

If such a functionality exists could you please "remind" my brain.

Thanks,

Daen

SolidworksSketching