Changes in Baseline in P3e

Hi Planners,
Can we make changes in baselines.
Like I updated my shcedule and assigned baseline. Now I want to change baseline duration, start and finsh dates of few activities.Is it possible??
I have tried but it couldn’t gone through.
How can I make more then two baseline and assign on Schedule. Becasue in "col edit" manue only two baseline options are available.
Waiting for reply.

Thanks
Minhas