Change the output style 'bibliography number' from numbering to lettering

Grateful if someone could advise how I can change the output style ‘bibliography number’ from numbering to lettering. Specifically, starting from A continueing to Z, then AB to AZ, then BA to BZ and so on. eg.

A.   " This is the 1st reference"

B.  " THis is the 2nd reference"

Z.  " This is the 26th reference"

AA.  “This is the 27th reference”

AZ.  “This is the 52nd reference”

BA.  “This is the 53rd reference”

BZ. “This ist he 78th reference”

Cheers

Bob

I’ll assume it can’t be done?

Not using Endnote.  I think the best way to do this is to use Word’s footnote/endnote capabilities and a footnote style.  You can insert endnotes in Word, an use the Alpha choices and I believe once you use up the letters, AA is the next option, I assume it produces what you are looking for. 

So an endnote style like Chicago 16th footnote and turn off the bibliography – which I just created for another thread here

Thanks for your reply. We are currently using the inbuilt Word endnote capabilities. Unfortunately, word’s next option is AAA, then AAAA.  This gets vary hard when you have 200 references and you have to start counting the number of letters. (eg 6xA’s vs 7xA’s, ie AAAAAA vs AAAAAAA). Not to mention other nuisances (broken cross references, duplicate references, manual ordering etc) we would like to move away from the inbuilt word endnote.

Could you perhaps provide me with an example word doc that achieves the combined  Word’s footnote/endnote capabilities and a footnote style to this effect?

Much appreciated.

Sorry, I only went so far as to add 27 (which was painful enough) and assumed it would be the way you wanted after that!!  I notice that OpenOffice does the same thing.  Who is the publisher?  Perhaps that have an in-house fix.  I have never had to confront this problem. 

(PS - I am just another Endnote user and not associated with TR or Endnote).