Portamento.
Adjust the timing to suit your preference and then apply it to whichever base sound you want to use.
You could then assign Portamento On/Off to a foot pedal to apply it when you needed it.(if that option exists)
That is one way to do it.
Maybe not the best, but certainly one way.
Regards,
Dennis L. Almond
aka...TwoNuts
[This message has been edited by TwoNuts (edited 10-10-2007).]