Different sidebar for page and blog post

Hi,

I need to have a different sidebars for regular page and regular blog post - the main layout is the same, but I need to have a completely different content in each sidebar (on the page: the submenu, on the post: the blog related stuff).

How can I achieve this? Basically I would need to add an extra sidebar (lets call it right-sidebar2) and use it for the blog post. And for the regular page I can use the default right sidebar.

I know, how to add the new sidebar, but how to connect it with the blog post, since all the predefined layouts use the same predefined sidebars?

I can deffinitely make may own template for the regular page using a child theme, with hardcoded reference to the sidebar, but I wonder, whether there is the other way, which respects more your original theme.

Thanks