dkal, where morph++ is definitely required for other characters, yes, it does need to be loaded first. 

Now, all morph injection do not work the same way.  A fair majority will change the model mesh once you double click on the character injection icon. However, others will simply load a morph dial into the Properties/Parameter palette where you will need to set the dial to 1 to transform your model.  I would imagine this is how Mec4D has arranged the injection to work.  In this instance, you can dial up or down the old man intensity on the model, or include varying degrees of other morphs to completely change the features entirely.  IIRC, the morph++ package for both V4 & M4 have already built in characters to change their overall appearances.  You just need to find their dials and set those to 1.