Create your custom model/view
Maybe you would be better if you would create your own model/view with its menu item and use it for that page. This would be somewhat easy - simply duplicate the core model/view you want, do any renaming where necessary and then you can write your own queries to fit your needs.
Before going that far though, make sure that you have covered all other possibilities and workarounds that may be more than adequate for your needs. So, although you have not gone into details about what your final goal is and all the why's, here are some suggestions that maybe you have not realized they do exist.
Use different/more categories.
For example, I want to point out that an article will not appear in the blog layout of a category if it belongs to another category. So, working around this you may have a real simple solution: Just change the articles category. In case you still need a good categorization organization, you could go a step further and create that with subcategories and separate the articles of that parent category to those that are to be displayed in the blog layout than those that aren't. Then in your menu item simply select the proper category and adjust any of the other settings like showing child categories articles etc.
Use Featured Articles
Also, from your question above I see you mention menu item with id = 101. Usually the 101 is the default id of the home menu item and by default this is the featured items menu item. So here maybe it worths pointing that you can have FEATURED ARTICLES blog layout per category that will display only those articles marked as featured.
Use articles status
Finally there are even more options - depending on your needs. You can set an article to UNPUBLISHED status - this will make the article totally unavailable from both the blog layout and as a whole. But there is also the ARCHIVE status available, which will remove the article from the blog layout, but it will remain available and accessible - either from a menu item or directly. Something that seems very close to cover exactly what you have described above - while keeping those articles under the same category.
code <?php foreach ($this->intro_items as $key => &$item) :
Inside put:code $this->item = &$item; if(!in_array($item->id, $extarticles)){ ?>
Remember to close if below right before the end of the foreach. On this example $extarticle is a array with ids.