You can substitute palm kernel oil (not palm oil) or babassu oil for CO -- these three fats have roughly the same fatty acids.
If you don't have any of these 3 fats, you probably need to rethink the recipe to be more of a lard-palm-tallow based soap. Add bubble-age with castor, if you've got it, and/or sodium citrate, sugar, beer, or other additives that encourage lather. I might also add a goodly dollop of something like olive.
If you post the recipe and the oils you have on hand, maybe we can suggest reasonable alternatives.