[Zope] Link to a script from ZPT

[Borislav]

Hi,

I am having the following problem:
In a ZPT I have a HTML link that points to a python script. I want to 
pass a parameter to the script. What is the right TAL expression to call 
  the script passing it a parameter?

I tried
<a tal:attributes="href python:here.myscript('arg')">Link</a>
but it replaces the href attribute with the output from the script, not 
what I had in mind...

I would appreciate your help.

Regards,
Borislav