Attaching eyelashes to an already existing character that has none

Hello to all, and happy new year! 

I am trying to figure out how to add eyelashes to an existing character that does not have them. I have modeled two plane geometries in another application, and fit them exactly upon the character's eyelines, upper and down. However the said planes will not follow the character's facial morphs in posing and animation. 

How can I eliminate this problem? The character is not a genesis character nor one made after the relrease of DS 4. Can someone knowledgeable explain to me how can this be done?

I am not sure if this discussion topic was made again in the past. If so, any moderator can direct me to the said similar post, and delete this one.