[Zope] DTML to search a lines property in a DTML Document?

[complaw@hal-pc.org]

Can you, using DTML, search a lines property of a DTML Document to look for a
specific string?  I have a set of DTML Documents with a custom lines property
(called, e.g., "doctrines") and I want to search through the list in the context
of a conditional statement in order to filter out the DTML Documents that don't
have a specific doctrine in the doctrines property (or list those that do).

Has anyone ever done that or something similar?

TIA,

Ron