[TYPO3-dev] Overriding $MCONF ?

[Patrick Gaumond]

Is there a clean way to override $MCONF values like we can do with $TCA 
in a extTables.php file?

I need to override the tstemplate module conf.php:

$MCONF['access']='admin';

replace with

$MCONF['access']='user,group';

Thanks for any hint.

Patrick