[Grammar-Kit] define tokens in .bnf which reference other tokens

Hey,

i am developing a custom language plugin.

I have a .bnf file with declared tokens. The problem is that i can only work with regex within the .bnf file. In the flex file i can reference other tokens e.g.:
https://github.com/JetBrains/Grammar-Kit/blob/master/src/org/intellij/grammar/parser/_BnfLexer.flex
ID_BODY = {ALPHA}
ID = "<" {ID_BODY} ">"

Is there a way to do that within the token attribute from the .bnf file and then generate the flex file?