If you are unable to drive the car away from the pound yourself, perhaps because of problems with your licence or insurance, you may be able to arrange for it to be collected by a specialist vehicle recovery company. You cannot, however, just ask anyone with a vehicle transporter to do this for you. Vehicle recovery is a very specialised business which is rigidly regulated, and costs may be relatively high. You must, of course, balance this against the cost of losing your vehicle completely, if this is likely to be the end result.
The staff at the pound wouldn't be able to recommend a company that could do this for you but they should be able to give you the names of some who would be acceptable and you would have to decide for yourself which ones to deal with.
First of all, however, you would need to attend the pound in person and produce the documentation detailed on the "how to collect an impounded car" page. They would also need:
1) a signed letter of authority from you
2) a copy of a valid document containing your signature, such as your passport or driving licence. Some authorities may require to see the original document, not a copy
3) a current driving licence and, perhaps, additional proof of their own identity.
All accumulated fees would have to be paid up to date before the car could be taken away.
If the car was still uninsured it would have to be be stored off the public highway and a Statutary Off-road Notification made until you were able to arrange an insurance policy. This should be easier to obtain now that the car was no longer in a pound but you would still have to inform the insurer of any notice of impending prosecution that you had been given and this may limit the number of insurers willing to offer a quote.
A motor trader will not, usually, be able to collect the vehicle for you, since motor trade policies almost invariably specifically prohibit this unless the trader actually owned the vehicle at the time that it was impounded.
In theory it should be possible to nominate a friend to do this for you. However getting insurance for this is extremely difficult. Virtually every policy that covers driving other vehicles specifically excludes impounded cars and even specialist insurers will only provide cover to the actual owners.
Please remember that these are general guidelines only. The exact procedure may vary slightly from one police authority to another.