How to find an operator with the desired code in 8-800?

Question

Telephony

The company needs a number like 8-800-773-xx-xx. Where to look for an operator with the desired code?
There is a code-operator list on the wiki , but the required code was not found there (only 775).

Answer 1

http://habrahabr.ru/sandbox/74328/

Answer 2

Thanks for the material, but I can't find the desired number using these databases :(
If you call the numbers 8-800-773-xx-xx, the answering machine reports that the number is not in use.