webuserlogin from another site

Hi
I dont know if this is the right place to post.. but here it goes
Is it possible to login as an webuser from another site?
More specific: I have a cURL-script, which logs in, logs out an user on the same domain, but in another system. I have implemented the script as an snippet to my testsite, and it works if I call the script in every snippet. But what I want to do, is to intergrate it, so I can use MODx (Revo)’s authentication and only call the script once on every pageload. Is this possible, and how can it be done?

Can anyone help?
Thanks

Sure, it can be done using Plugins and Events, but you’ll need to better describe your specific goal or requirements here before anyone can offer much detailed advice. What is the other system? How long can the login from this system be considered active? Do you have to check on every request? etc...