wp_get_archives problem with

Hi,

I have a line in my theme which shows my latest 7 posts:
<?php wp_get_archives('type=postbypost&limit=7'); ?>

Now that line works ok but what I want it to do is show the latest 7 posts but from category number 10, I thought this would work but it doesn’t:

<?php wp_get_archives('type=postbypost&cat=10&limit=7'); ?>

Any ideas on how I can get what I am looking for?

Apologies but I am new to this so there may just be a glaring error on my part but your help is appreciated 🙂