RE: Rule from param and 2 Vals for keys

> Hello,
> Is it possible to invoke a select or test or other xpath query from
> the value found within a variable or param?

You need an extension such as saxon:evaluate() or dyn:evaluate in EXSLT.
> 
> - ALSO - 
> 
> How can you create a key for the following, where "ABC" and "XYZ" and
> "xxx" are all the values I'd like to supply to the key for matching:
> 
> /root/recordset[@rsName='ABC']/record[field[@fieldname='DEF'] = 'xxx']
> 

I'm not sure I understand the question. But you can define a key

key match="field" use="concat(../../@rsname, '#', ., '#', @fieldname)"

and then replace the above expression with

key('k', concat('ABC', '#', 'xxx', '#', 'DEF'))

Michael Kay
http://www.saxonica.com/