I\'m making use of the following code:
.c-1:first-child, .c-2:first-child, .c-1:nth-child(4n+1) { margin-left: 0; }
which is working great but
You can use jQuery's .eq(<index>)
for this.
For example:
$('.c-1').eq(0).addClass('remove');
There is a library that will polyfill the missing CSS features in IE:
http://code.google.com/p/ie7-js/
Using the IE9 version will give you access to :nth-child()
according to the feature list: http://ie7-js.googlecode.com/svn/test/index.html
Maybe check out the following article:
http://abouthalf.com/2011/07/06/poor-mans-nth-child-selector-for-ie-7-and-8/
But the described solution works only in ie7 and 8, in ie6 it won't unfortunately
I suggest use http://selectivizr.com/
For pseudo-elements IE8. I know its old post but maybe some1 will find it usefull :)