substitue strings in xsl

I was wondering if someone had a clever way of doing this.

say i have an xsl variable set to:

"you have 1 message(s)".

i want to change it to:
"you have %1 <a href="blah">message</a>"

and somehow use an xsl template to substitute %1 with a parameter passed value. the problem i have is that the <a> tag gets stripped out when i use 'substring', since it treats the string as a string, cutting out all nodes.

any ideas/clues/tips??

thanks.

I'am not sure I'am quite understading you.

Perhaps you could show us what you have done so far.