Yes you should be able to add it to your existing CPH quite easily. In England, land within 5 miles of your base holding can be added to your CPH, and treated as one single holding, with moves and standstills applying as if one single parcel of land.
Simply talk to the RPA - not sure if it's a form, let us know!
There are advantages and disadvantages for both you and your neighbour in how you do this.
For instance if your neighbour already has a CPH that covers this wood and other land of his, then you could as OTG suggests you leave it under his CPH, then any moves between the two would need an e-aml. But it would leave you free to say buy and move pigs into the wood, whilst still be able to sell weaners from your existing holding (as they are treated as two separate holdings). You can then move any bought in pig after the 21 days to your existing, allowing you some flexibility and freedom in selling. However this scheme would put your neighbour on standstill every time you move pigs on, and the woods you rent on standstill every time he moved livestock on his bit.
If you take this wood into your existing CPH, then you manage it as one, so any move on creates a standstill against all. But both your and your neighbour can freely move stock without affecting each other.
Finally some transgressions of law go against the CPH holder irrespective of livestock ownership, so if CPH left with him he could be liable for things you do !
This is a complicated area, but generally I would recommend that you add it to yours.