Hi Andy,
Zope, and python for that matter, have no for loops ;-)
Try this (untested, someone please correct errors ;-):
I'm assuming stringthing (eg "Root") and numberthing (eg 0) are
attributed of the objects in your sequence list.
<select>
<dtml-in sequence>
<option value="<dtml-var stringthing>">
<dtml-var "' ' * numberthing">
<dtml-var numberthing>
</option>
</dtml-in>
</select>
cheers,
Chris