How to use portamento in sequence ?

[mascob]

Hello every wavestate specialists.
All is in the title.
I try to create a sequence bass line like the famous "equinoxe 7 " by JMJ.
The particularity of this bass line is to use a great analog bass sound with a portamento effect on some notes...but I don't find the function to do it on the wavestate. The portamento function doesn't work on a sequence...apparently it only works with a single multisample.
I suppose there is a trick to do it...but I don't find...
Many thanks for your help !
Mascob.