Use the Dictionary suite to add meta data to the art dictionary.
Thank you for your return. Can you give me more details.
NB:"I have a text in illustrator file witch contain many of translations. My objective is to identify the begining and the end of each translation.
You could take a look at AITagSuite.
You would find all the methods you need to tag an AIArtHandle.
-> SetTag, GetTag, .......