Trilian - MIDI foot controller pedal board - BIG PROBLEM

Hi to all.

I am pianist but I also play bass lines with my left foot. 

I am using Spectrasonics Trilian and can not figure out how to make it playable.
On my Hammond organ I had one knob which controlled sustain time. 

My playing style is as follows. 
* both hands playing keys.
* right foot on sustain pedal for piano only
* left foot bass lines

I play bass lines with my left foot only and would like them to sound connected (sustain or legato). It would be great to control the sustain time. As of now all I play is staccato. Sound disappears as soon as i release foot key/pedal. 

Any help ?

Thank you very much
Kawai MP11
Roland PK-5A


P.S. I know that i can have sustain with additional pedal but my right foot is taking care of Piano sustain already.

Hi Thanks for reply.
Could you be more specific ?
How to do this ? Do I need additional plugin ?
It would be great to have it on my master keyboard knob and regulate the time. 
For example longer for ballads and shorter for dixieland.
Literally I spend years on that and can not figure this out.
 
I love Trilian because it has the most realistic bass sounds.

Sorry, while I have fixed the bug, I forgot that I still do not have time manipulation functionality in my plug-in. And it is unclear when/if I implement it.
 
Looking in the documentation (I do not have Trilian nor PK-5), PK-5 ( http://cdn.roland.com/assets/media/pdf/PK-5_OM.pdf , page 10) has "Hold" function in "Bass" mode. If I understand it right, you should be able to play legato using it.