Well sure... I don't see why not you simply need to edit the appropriate templates and add in the code unless I'm completely missing something.
Where do you want it shown (bear in mind some ad sizes like 728 x 90 may or may not fir aesthetically into your site/style) in your CMS, in the articles correct?
Edit: If it's in the article pages themselves this can easily be done however on the preview page it would take some work...
Go to your style manager and select to edit your templates... find the template named vbcms_content_article_page and edit it, now find:
<div class="fullwidth">
Add below:
*This would be your add code I removed my pertinent details and replaced with 123 and as usual the 8675309 song number lol!
<script type="text/javascript"><!--
google_ad_client = "ca-pub-1234567898675309";
/* Main 2 */
google_ad_slot = "1238675309";
google_ad_width = 468;
google_ad_height = 60;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
Demo screenshot:
https://vborg.vbsupport.ru/external/2010/12/31.png
See if that does what you want, you may want to relocate it if your not happy with the location.