How to deal with modified SMILES

[lixinyuu]

It is quite impressive that ORGAN model can direct learn molecules' properties by the SMILES string. My problem is I have a modified version of SMILES which take the van der walls force into consideration. For example, the carbon atoms in an ethane molecule have impact of van der walls force of another two carbon atoms, I added a {[C]} after each C character.
So the SMILES was modified from CC to be C{[C]}C{[C]}. However, this did not obey the SMILES grammar, and can not be recognized by the RDKit. Is there any method I can implement this kind of SMILES in ORGANIC?