Trying to obtain my Egyptian registered birth certificate

I was born in UK in 1960,of an Egyptian father, English mother.  My birth was also recorded in Egypt & accordingly I have dual nationality. I lived in Egypt from age 8-21 then moved to back to Britain where I have remained for 35 years. I officially anglicised my name when I returned to live in Britain and am married with adult children.
When my Egyptian passport & identity card expired nearly 30 years ago I didn't renew them, as the embassy informed me they could only renew documents in my original Egyptian names, meaning I'd have British & Egyptian passports in different names which would have looked very suspicious. As I had no need of them at the time, I let the matter rest and took no action. Have since tried several times to renew my Egyptian ID but I don't have a copy of my Egyptian birth registration, recorded and held in Cairo, and without that,I am told,no new documents can be issued to me. Relatives in Cairo say that the certificate can only be retrieved from government offices by the named individual on them, or someone with a valid power of attorney, but this cannot be made without valid Egyptian ID documents which I can't make without the official Egyptian birth registration document. My British birth certificate is not enough. Current UK ID documents I possess are in my anglicised & married names so bear no resemblance to my original Egyptian name. The Egyptian embassy in London says they can't help. Am at my wits end. Can anyone advise if there's anything I can do?