can there be variables in the xpath expression

[Tahura Chaudhry]

I am using xalan-java to evaluate an XPath expression for a given XML 
document.

Is it possilbe to write an XPath expression with variables and have 
xalan-java evaluate the expression with supplied values for those variables.

For example, write the expression as:
foo/[EMAIL PROTECTED] and @last=${b}]
and supply the values 'John' and 'Jane' for the variable '${a}' and the 
values 'Doe' and 'Deer' for the variable '${b}'.

thanks,
Tahura Chaudhry