Grant/Revoke Create, Modify or Delete Connections in Designer Application

Hi,

I'm wondering if there is a way to grand or revoke the "Create, Modify or Delete Connections in Designer Application" by code for some specific users?

So basically I have a group that inherit the "Full Control" and inside that group I have the specific user that I want to revoke the access right to delete connections into the Designer program. Actually i have the following...But it's not working :

                IUserGroup oObjectGroup = (IUserGroup) executeQuery(this.FIND_GROUP_BY_NAME+_userGroupName+ "'").get(0);

                IInfoObject _obj = ((IInfoObject)_oObjectUser.getInfoObjects().get(0));

                ISecurityInfo2 _secu = _obj.getSecurityInfo2();

                IExplicitPrincipals _iExplicitPrincipals = _secu.getExplicitPrincipals();

                IExplicitPrincipal _iExplicitPrincipal =  _iExplicitPrincipals.add(oObjectGroup.getID());

                IExplicitRights _iExplicitRights=_iExplicitPrincipal.getRights();

                RightDescriptor rightDescriptor=new RightDescriptor(CeSecurityID.Right.DELETE,CeKind.DESIGNER, false);

                IExplicitRight iExplicitRight=_iExplicitRights.add(rightDescriptor);

                iExplicitRight.setGranted(false);

Can someone help me out on this?

Thanks