To create a morph and have it mirror-reflected on the other side, follow these steps:

1.Import model and Store morph of model at neutral pose.
2. Create symmetric morph using move tool with 'activate symmetry' selected in the transform pallete.
3.Save as ztl,with "symmetric" in  suffix of name.
4.Use morph brush on one side to restore that side to neutral pose and save this as another ztl.
5.Import symmetric ztl saved previously and then repeat step 4 on the  other side.
6.Export these two ztls as two mirror morph objs appropriately named.