File permissions issue

Hi. So I’ve created a slideshow plugin (Easing Slider) for WordPress, and been developing a new update that creates a dynamic CSS file.

This CSS file is created through PHP and then saved into a folder within the plugin folder. Having some issues though with file permissions. Some users hosting accounts don’t default to 755, and therefore not letting the plugin save this dynamic file, hence creating major issues.

How can I get around this? I don’t think explaining to various users that they need to change their file permissions is practical as many of them probably won’t know how too. Can you change file permissions through some sort of WordPress functionality? Or is there another method I can use that doesn’t involve loading the styling into each page’s header.

Thanks.