Here is a solution using biblatex 2.0/biber 1.0. You can define your own entrytype for this and then just write your own driver for the new type. Since you "own" this driver, you can do what you want with it, add new fields, format them how you like. This is very easy, I just copied an existing driver from the standard.bbx in biblatex and changed it a bit, making it a "standard" driver and referencing the fields I allowed for this type in the datamodel declaration (NUMBER and TYPE). You are really adding to the data model as this already specified that most common fields like AUTHOR, YEAR etc. are allowed in all entry types. NUMBER and TYPE aren't so I added them. I didn't have to actually define these fields in the data model as they already exist - you could of course make completely new fields with new names but then you'd need some \DeclareDatamodelFields declarations. See section 4.5.3 of the biblatex 2.x documentation.
\begin{filecontents}{test1.bib}
@STANDARD{test1,
author = {Alan Author},
title = {I Claim This Technology},
type = {ISO},
number = {ISO 9241-210:2010},
year = {2010}
}
\end{filecontents}
\documentclass{article}
\usepackage[style=numeric]{biblatex}
\addbibresource{test1.bib}
\DeclareDatamodelEntrytypes{standard}
\DeclareDatamodelEntryfields[standard]{type,number}
\DeclareBibliographyDriver{standard}{%
\usebibmacro{bibindex}%
\usebibmacro{begentry}%
\usebibmacro{author}%
\setunit{\labelnamepunct}\newblock
\usebibmacro{title}%
\newunit\newblock
\printfield{number}%
\setunit{\addspace}\newblock
\printfield[parens]{type}%
\newunit\newblock
\usebibmacro{location+date}%
\newunit\newblock
\iftoggle{bbx:url}
{\usebibmacro{url+urldate}}
{}%
\newunit\newblock
\usebibmacro{addendum+pubstate}%
\setunit{\bibpagerefpunct}\newblock
\usebibmacro{pageref}%
\newunit\newblock
\usebibmacro{related}%
\usebibmacro{finentry}}
\begin{document}
\cite{test1}
\printbibliography
\end{document}

biber) the ISO number in a field that forms the citation label. Examples withauthoryearcan be found here. – Audrey Aug 03 '12 at 00:35numericas the citation style and currently I'm only using normal\cites, not something where the author had to be displayed. So I guess I could get along withnoteor something. But I was wondering whether there was a "proper" way to do it. And somehow, creating a new 800 line file and excluding myself from updates to the original didn't seem proper either. – Christian Aug 03 '12 at 14:19