Are you using a modeller, magnets or dial spins?

If you are using DAZ's Morph packs, they prefer either pz2 or inj/rem for morph distribution.

DAZ sells Injection Pose Builder and Injection Magic in their store.  Thorne has a tutorial over at Faerie Wylde explaining how to create a simple inj/rem pose in a text editor.

If you are using P6 and above, you have the option of saving the morph as a pmd.  Nerd3D has a tutorial on his site telling you how to create and inj/rem pose for pmd's using a text editor.

Many face morphs available at RDNA are in pmd format.  There is a script for DS that will convert pmd's and it is free.

Custom morphs created in a modeller are yours but you cannot simply distribute the obj file.  RTE encoder can be used to encode the file against the base mesh.  If you are planning to use RTE encoder, it's safest for you to check with DAZ and get something in writing giving you permission.  Some will say you don't need to but I always believe in covering my butt.