There is a way. This solution is strictly for small businesses, which I have done for my own. We wanted to keep our office number as we advertise it everywhere.
Go to tools -- > apps --> get apps... search for the add-on named "Zaplee" under the business section. Zaplee is a virtual call center on the cloud (which means: the software you would normally work with on your computer, you just do through your browser instead).
Contact their support via email or however you choose to do so and ask them if they are capable of "porting this #" listing the office landline you wish to use. They will let you know if they can port the number over (it's a $50 dollar fee for them to actually grab the number from the current provider, which for us, was Verizon).
I suggest looking into their service. That way you pay for one account to have credit, and everyone dials out through that account (therefore every person calls from the same number, which is your current office number). This way you don't even pay for an online number let alone multiple ones (minus the $50 port fee) and you only have to worry about one account having subscription.
We have 6 people currently using this service, and it's $10 per person to have access to this line a month. So it's that 60/mo plus whatever skype credit is needed to fund the dial out account (which to clarify, is a seperate business account/skype id made inside skype manager that no one logs into). You get personal greetings, voicemails, hold music, and program what order people receive calls based on availability. You can also set up departments (for us being personal lines/commercial lines). It's a pretty cheap solution despite how much research it may seem like. I am not associated with these people other than the fact I use their service and recommend it. Let me know if that helps. To me, it's a viable solution.
Also to clarify.. this is a service advertised by skype they hosted in their add-on section. It works with Skype, but it also works with google voice and I think a few other services. You still use most of the skype features through your open skype program, but you get access to a virtual call center as well. The main point is that you get to port your number over with these guys. It's listed as $10 bucks because it's 10 for each person to have full access to that dial out/in number.
If I helped, mark it as a solution so others can see. I've seen this question unanswered far too many times.
