BNF php string that may contain regex (Plugin for intellij idea)

I have such token to define strings

string='regexp:(["]([\\]["]|[\\].|[\001-\377])*["])'

This token is correct in PHP/GO languages but it doesn't work in my Intelij Plugin after generation custom language definition.

For example folowing string can't be resolved cause contain "\" before "d" "\d"

"/^[a-f\d]{24}$/i"

Question: how i can rewrite regexp to correct string/regex recognition?