Log into admin via POST request

Hi,

I wanted to add WordPress to an existing CMS – basically just have a button on there for ‘news’ on the old CMS panel which took them through to the WP interface. Is there a way of avoiding the double login though? (I can set WP admin user to have same pwd/username as the rest of the CMS). It’s only a small cosmentic thing but it would make it a smoother integration.

Anyone done this before and can offer a tip?

TIA

Kino