adding code to link function

hi. does anyone know if it's possible to add code to pop up a window of a specific size in fck_link.html.

i'd like to add a function to add some code as follows:
<A onclick="NewWindow(this.href,'name','400','300','no');return false;" href="products/herbs/comfrey.html">comfrey</A>


so i need to somehow insert the following into the link code that's being generated currently.
onclick="NewWindow(this.href,'name','400','300','no');return false;"

thanks for any suggestions