Yes...you can do this in clean/config.php by changing the THEME->layouts whic look like this...
For example:
Just make sure the file is column2.php and the regions are 'side-post' as I have shown the example below:
$THEME->layouts = array(
// Most backwards compatible layout without the blocks - this is the layout used by default
'base' => array(
'file' => 'column1.php',
'regions' => array(),
),
// Standard layout with blocks, this is recommended for most pages with default information
'standard' => array(
'file' => 'column2.php',
'regions' => array('side-post'),
'defaultregion' => 'side-post',
),
// Main course page
'course' => array(
'file' => 'column2.php',
'regions' => array('side-post'),
'defaultregion' => 'side-post',
'options' => array('langmenu'=>true),
),
etc...etc...