I am not sure what part of it you are having a problem with.
For the serial number, see the article "Creating sequentially numbered
documents (such as invoices)" at:
http://word.mvps.org/FAQs/MacrosVBA/NumberDocs.htm
For the year, use Format(Date, "yy") in a macro or a field { DATE \@ "yy" }

Signature
Please respond to the Newsgroup for the benefit of others who may be
interested. Questions sent directly to me will only be answered on a paid
consulting basis.
Hope this helps,
Doug Robbins - Word MVP
> ?'m working in a letter template, im facing troble to make a reference
> which
[quoted text clipped - 4 lines]
> thank you very much
> Elhaj