[xsl] Read data from a text file through XSLT template

Hello,

I am assigned with a task to access a file through my XSLT template and
read line by line the usernames/passwords from the flat text file and
store them into a variable. Or even access a database in order to get
the username/password and store it into a variable.

This variable will be used for the further transformation / XML
generation.
Is that possible?  I couldn't find anything useful yet in internet.

Many thanks,
Houman