Plugin WordPress JSON API - How get posts for category with offset?

[admin]

for example in category "news" of my blog there are 50 posts.
For get last 10 posts I do:
<a href="http://mywordpress.com/?json=get_category_posts&amp;slug=news&amp;count=10&amp;status=publish" rel="nofollow">http://mywordpress.com/?json=get_category_posts&amp;slug=news&amp;count=10&amp;status=publish</a>
And it work correctly.
Now I want to get my posts from 11 to 20 skipping last 10 posts, etc.
How can I do?