your question isn't making sense.
what do you meen by youv'e got a portal? is it a little script you would like to put into another page? is it an entire portal containing more then one file? what?
your host should provide you with instructions on how to upload files to your server. generally this is done via ftp.
most servers are setup so that either index.php or index.html are the default pages. this means, if you put an index.php file in your root directory then typeing your address in a browser should display that index.php file automatically.
