Shared SSL certificate, can't enable module

Hello all, I have been trying to get the secure pages module to work with my shared ssl certificate but I am running into some problems. When enabling the module I go to configure it and the enable/disable buttons are greyed out. After reading posts with the same issue I am unclear as to whether shared ssl can be configured to work with module.
I have tried logging in through my ssl but it only shows the secured home page and comes up with an 404 error when I try to log in so I can't enable the module in a secure enviroment(which was suggested in another post). I tried changing the $_SERVER['HTTPS']!="on" in the secure pages module to "1" which didnt work either. I have contacted my server about why I can't access the entirity of my site using my ssl and this was their reply:

Please take a look at the info at this website to see if it helps: http://crackingdrupal.com/blog/greggles/drupal-and-ssl-multiple-recipes-...

Please note that we do not provide coding/scripts/software suppor but you could also try this code which you will need to customise:-

function redirectToHTTPS()
{
if($_SERVER['HTTPS']!="on")
{
$redirect= "https://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
header("Location:$redirect");
}
}

I have no idea how to configure this or where to put it if I got it configured as my php knowledge is 0 (my lamens guess would be to put it in settings.php or somewhere within the module, probably wrong, so out of my depth lol )

My shared ssl is web133.secure-secure.co.uk/mywebsite.com if that helps.

Any help would be greatly appreciated, I really do need to use my ssl as I am creating a small ecommerce site. If shared ssl is going to be an issue with this module I guess I will have to look into purchasing one and hopefully that would work.

Thanks :)