I downloaded polymorph plugin but my hosting firm doesn't allow open_dir code in sma. I can't upload .amxx to that host. Can You edit this plugin without open_dir code?
If they don't allow you to upload .amxx files, then how are you supposed to even update the plugin?!
What's the point of them even disallowing "open_dir"?
How do you expect to use a plugin that needs to read all the files in a directory in order to work?
Here's what you should do - tell them that you will be moving to another host if they don't allow you those stuff. And then actually move if they don't listen. There's no point in using such a terrible service.