Help with context-free grammar of lots of literal text with some special syntax

How do you make a context free grammar that analyzes mostly literal text (spaces, characters, symbols, etc.) while also looking for expressions of the form ${...} or $someComma开发者_Python百科nd{...}? Note if it finds "I got $10 today", it should not do anything special with it.

Is it possible?

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Yes, it is possible.

Since this is the right answer, I believe you will accept it.