I have just discovered that this code works in my config file.
format CL1Vlist "<span>[srclink]<img alt='[dc.Contributor]' src
=/gsdl/collect/gsarch/index/assoc/[archivedir]/thumbnail.gif>[/srclink]</span>"
(note the lack of quotes in the HTML)

I have also used the same technique to include a target=_blank when
refering to a source file.

Is it ok to use _somethingortheother_ in format statements?

Stephen