JSF Manipulate onclick value

I'm new to JSF (and seam) and am trying to figure out what's possible. I've got the following output link. When my view renders, I need to manipulate the "#{myClass.myString}" value on the onclick url. I tried this:

Code:

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#{myClass.myString.replace(...)}

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, but that didn't seem to work (is it supposed to?).

I've used validators before, but wouldn't that only work on the outputLink's "value" property? Is there a way to run regular expressions in the view?

Code:

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<h:outputLink value="#" style="text-decoration: none;align:left"
  rendered="#{myClass.fileYn.equalsIgnoreCase('Y')}"
  onclick="window.open('downloadFile.seam?fileId=#{myClass.infoId}','popupWindow')"> 
  <h:outputText value="#{myClass.displayText}" />
</h:outputLink>

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