I bought a van that was registered in Spain, I contracted a transporter to deliver the van which he did but somehow he lost the legal documents of the van.

I have sued him but the thing is, that he bears a different name on the company house details, which means that I cannot sue him for negligence (the legal papers were collected from the seller but never got delivered to me, which makes the van illegal to drive in the UK).

Several attempts had been made on my part to trace the documents but the transporter shows no concern hence the reason I have sued him in the courts

Now the court wants me to identify with precision why my claim is against the name of the director in company house listing

At this point I must mention that this transporter has several names and several addresses and this is why it is getting almost impossible to sue him

You should have a written contract, you must sue the person named in that contract.

You may also sue other identies of you can prove they are connected to the transport.

... Now the court wants me to identify with precision why my claim is against the name of the director in company house listing
...

Are you suing the director of the company or the company? It it was here in the U.S. you would sue the corporation, not a director of the corporation. Is the court is saying that you have named the wrong party?