Hi.
Yes you can
1st you need :
using HutongGames.PlayMaker;
then a variable for the fsm :
public PlayMakerFSM myFSM;
if the script and the fsm are in the scene from the start, then you can drop in the fsm.
if you need to get the fsm from another object, select the object with the script
Then on the inspector click on the lock to lock it.
then click on the right side of the lock, select add tab and select inspector.
you will now have 2 inspectors drag it somewhere so you can see both inspectors and the select the object with the fsm you need.
now you can drag in the fsm.
Another way to get it is for example like this :
myFSM= gameObject.FindWithTag("tagOnMyFSMobject").GetComponent.<PlayMakerFSM>();
to send a event you can do :
myFSM.Fsm.Event("theEventToSend");
you can find some API references here :
https://hutonggames.fogbugz.com/default.asp?W127