regsub problem

From: Amit Singhal (asinghal_at_noida.atrenta.com)
Date: 10/29/03 

Date: Wed, 29 Oct 2003 12:59:18 +0530

Hi

I have the following statement :
  set tt {[check_format stmt]}

No I intend to substitute [ with \[ and ] and \]
or in case if this is not possible is there a way I can substitute
[ and ] with "

Thanks
Amit