Escaping curly brackets in SC's SQL macros

I have an sc_exec_sql update statement with “…WHERE narrative REGEXP ‘[0-9]{20} [0-9]{8,10}’ AND…” which does not work (works when pasted directly in phpmyadmin though so nothing wrong with the statement)

I realized it must be due to SC’s interpretation of curlies.

How can I escape it in SC? Have tried these 2 but they don’t work :

a) …WHERE narrative REGEXP ‘[0-9]".’{20} [0-9]{8,10}’."’ AND … // this returns no error too and still does not work
b) …WHERE narrative REGEXP ‘[0-9]{20} [0-9]{8,10}’ AND … // this gives a PHP syntax error

Bump! Does anyone use MySQL regular expressions in SC?