You'll have to some work here yourself because I don't know where you're coming from !!!!
The sites below allow you to input a start and finish destination.
If you're travelling from the North I would recommend you input Bournemouth or BH8 8DL as your destination or way/via point as the road is a lot quicker this way, (past Bournemouh Airport) .Once in Bournemouth you can pickup the signs to Poole and your destination BH15 1UX.
Sat Nav put BH8 8DL as your destination, this is an Asda store next to Bournemouth Station, when you see it on your left simply re-input BH15 1UX and carry straight on !
From North London we can do the journey in 2 hours with no traffic.