IFM Manager where clause condition for active instances

Hi

we have requirement to add the viewer security for some of the process instances for one of the group. we are trying to user the IFM Manager node with the following Query

UPDATE <process model id> ADD_SECURITY [VIEWER] =  [<Group constant>]  this is working as expected. but we need add this security to active instances only. how to that where clause in the query.

we tried UPDATE <process model id> ADD_SECURITY [VIEWER] =  [<Group constant>] WHERE [c8=0] its giving impacted instances are zero.

Can some one help in provide the exact where clause.

Thanks in advance.