[support] How to override this variable?

Hello list,

can anyone be so kind to tell how (and if?) is possible to override in a multisite two variables coming from the Category_default.module initially looking like:

INSERT INTO `variable` VALUES ('catdef_storylink_50', 'i:0;');

so that they finally look like:

INSERT INTO `variable` VALUES ('catdef_storylink_50', 'a:1:{i:0;s:2:"75";}');

?

I've tryed in different ways, but keep getting errors:

1. using the whole string: 'catdef_storylink_50'=> 'a:1:{i:0;s:2:"75";}',

2. using only what's in between graffles: 'catdef_storylink_50'=> '{i:0;s:2:"75";}',

3. using only the number of the category: 'catdef_storylink_50'=> '75',

i keep getting the same error:

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting ')' in /public_html/drupal/sites/mysite.com/settings.php on line 162

starting doubting this is actually possible...

Thanks lot

marco