How to own an already sold domain name to build my dreams.

You can contact the domain registrar to get information on the status of the domain name. Some domain registrars contact the domain owner and offer a buyback price.
Since I have a Go Daddy domain, I can cite the example of the offers they have. They have two kinds of service when you want a domain that has been taken.

Buy domain service
The registrar will contact the owner of the domain name. If the owner is ready to sell the domain, they will arrange a buyback. But the price is much higher than for a regular purchase.

Back order
If the back ordered domains are inactive, they go for domain auction. You have to be real fast to register yourself for the auction. Further details can be obtained from the registrar web site. The domains that have not been renewed or inactive for an extended period of time generally go for auction. This option too will be quite costly. I would suggest you to opt for it only if you are sure that the name makes a huge difference to your business or the dream as you stated.

I assume almost all domain registrars follow the similar procedure with the already taken, but inactive domain.

I would advice you to refrain from hacking into the domain name. It would amount to an illegal practice and you will be liable for punishment under cyber crime guidelines.

Domain if not under trademark can't be acquired by legal means easily. Even with trademark, the person who owns the domain needs to be in your country. So your business is from India can't impose trademark in US. Unless you have business established in US too for the treaty related cases to work.

Trying to get the domain name by illegal means such as braking into account will make your case weak. So if you want to build a business then try to remain professional and follow the rules and laws to keep the reputation.

You have few options -

1. Reverse Lookup : This method allows you to find out the domain name owners details. It'll cost you some money to find the real name of the person. And once you find it out the name you can make your quote.

2. SEDO : Ask sedo for the domain price bidding service. In such case they offer the bid price on your behalf. And from there you can professionally approach the domain owner. And you have to pay the price for which the domain owner agrees along with commission or one time price for that service. Service also keeps track of the inactive domain during escrow transfer.

3. Inactive domain backorder system: In this option you have to wait till the domain gets inactive or not renewed by the owner. During that period you can quote and buy the domain. It's too tiresome method but there are high chances of getting the domain back at low cost too.

There are few other methods but I'd suggest keep the legal and professional route open all the time if you want to be in business. That being said, there are many other methods you can try by legal means as well assuming you have enough credentials in business.

Once check it out in any domain service providers and if it's unavailable then go through the details using who is and contact the domain holder and offer him a price and make the deal with him.

If you can't find details of him, you can use sites like SEDO where they take over the issue and contact them with a price.

If none of the options are working, its better to go for another domain rather than wasting time on this.

You can't hack that domain, its just waste of time and its also illegal.

If the Domain Name of your dream is still inactive then you have quite a good chance to own it. You can try these ways.

1. Go to www.whois.net, there you can search for that particular domain.
They would come up with the information to whom it belongs with some more information as well.
Then you can definitely contact that person and ask for a deal.

2. Wait for a few more days and keep searching for that name if it comes available, since it is inactive.

3. If the name has a .com extension you can book the same domain name with other extensions like .in, .co.in, .net and so on. This will make that particular domain name hold less value.
So the owner might feel like releasing it and you can have it.

Hope that works.