Dial up on a multiline phone

Hello Dell forum,

 

I've been recently moved to a new office where they installed new phones and put a multi-line phone on my desk instead of the old single phone line. Since then I can't get a dial tone to dial up to my own internet. Is there any sort of filter or splitter that I can use to dial out on this phone?

 

Thanks for any suggestions.

 

Oloughma