[phenixbb] How to include restrains to DNA as A-DNA or B-DNA

I am refining a protein-dsDNA complex structures at 2.4-3 A. Based on the phosphate distance, I can predict if particular nucleotide is A DNA (C3’-endo) or B DNA (C2’-endo). I want to add restrain to to the specific nucleotides as A or B DNA. But secondary_structure_restraints for nucleic acid does not seem to have options for this. Any suggestions? Thanks