If you want to activate or deactivate the backslash support in a stored procedure you can use the following two special comments (on a separate line) :

--no_c_escapes+

turns the backslash escaping support off (insert into x values ('c:\test') will result in 'c:\test' in the column

--no_c_escapes-

turns the backslash escaping support on. (same as above will insert 'c:test' in the column.)