block and other options

I'd like it if the filter would insert the Amazon IFrame blocks. An example would be:

<iframe src="http://rcm.amazon.com/e/cm?t=<% $associateid %>&o=1&p=8&l=as1&asins=<% $ASIN %>&fc1=000000&IS2=1&lt1=_blank&lc1=cf0000&bc1=000000&bg1=ffffff&f=ifr"
style="width:120px;height:240px;" scrolling="no" marginwidth="0" marginheight="0" frameborder="0"></iframe>

Where $associateid and $ASIN and the surrounding <%%> markers would be replaced with the appropriate text. I implemented it myself in two lines, but it had my associate ID hardcoded into it.