[xsl] separating string values without tokenize()

["Charlie0 charlieo0@xxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

I am sure this has been addressed here previously, but I can't find what 
I'm looking for in the archive.

I have this string:

'R0052, R0055, R0057'

I need to create this XML output:

<xref figid="R0052"/>, <xref figid="R0055"/>, <xref figid="R0057"/>

I am restricted to using XSL 1.0. (this is an easy problem for 2.0, but 
I cannot use the tokenize() function).

This specific string has three values, but the string could contain two 
or more comma (and space) delimited values.

How do I get this done with XSLT 1.0?

Charlie O