[Zope] " in a let

Hi all ! Has anyone accomplish to create a string in dtml which has a " (quote) something like <dtml-let my_str="aaabbb " aaabbb"> </dtml-let> I have tried the normal escape character \ but it didn't worked !!! : ( <dtml-let my_str="aaabbb \" aaabbb"> </dtml-let> I think that the use of " in a string is a problem in redering dtml !!! am i wrong !!! please tell me that i am !! regards Nuno