How can i go from HKAirport t dongguan hotel regal palace by limo,where to take , how much cost?

Many car companies offer such kinds of services and this service needs to be booked in advance.
The buses can be taken at the Coach Station, T2, but for different car companies, they have their own positions in the coach station.
For the detail price and the exact position, you may need to ask the car company directly. For the contact information of different car companies, you can find them on the official website of HKIA.
Hope you can find them~