As fas as you are talking about inputting a bass slide on a sequencer (no real time playing),
1) maybe a carefully programmed portamento slide can do the job. Portamento on, slide, portamento off. (maybe you also have to send the portamento time for better effect.)
2) or, supposing that your bend value is the normal 2 semitones, an instantaneous setting of the bend value to 12 semitones and the "drawing" of the bend with a mouse" and then back again to 2 semitones.
Never done any of this, just thinking aloud.
maybe this will help regarding the CC numbers http://www.tweakheadz.com/midi_controllers.htm