What is the best way to split a line pulled from an on input script ($1-) to be split to two differant external files (via /write). The split will occur when an 'http://' occurs.

i.e.:
<MyUser> Go read this web site at http://www.random-nonexistant-site.com

Text1.txt "Go read this web site at"
Text2.txt " http://www.random-nonexistant-site.com"

Any ideas?