Sending Text Messages via Orange.co.uk

I am a Orange Pay as you Go user and have just signed in to the orange website, where I can send 30 free text messages a month (through the website)

But can anyone tell me can I send messages to those short text numbers for example Sky News say that you can text them on 84501 can I use the Orange website to text them on that number?

Also I tested my account by sending myself a Text and it appears in my Text Inbox on my phone as a 4 digit number can I change this to be my number.