CSV-to-XML in XSLT 1.0 via input-file and tokenize

I'm a beginner in XSL. But, wanting to do XSL all the way, I searched for an CSV-to-XML done as XSLT and found Michael Kay's rather slick implementation: see www.oxygenxml.com/archives/xsl-list/200606/msg00522.html ! 

But unfortunately I can't get it to compile in my processor, nxslt3 (docs at www.xmlLab.Net/Downloads , especially docs under version 1 (nxslt1))) --even though nxslt includes EXSLT (www.exslt.org) featuring stuff as tokenize (www.exslt.org/str/functions/tokenize); my guess is because this code is in XSLT 2.0 (its use of: unparsed-text, $input-file, as, tokenize). 

How would this elegant code be rewritten so it works in XSL 1.0 (specifically NXSLT3 featuring EXSLT)?   Thanks!