How to assign a variable post xslt transformation

In many working scenarios , we come across a situation , where a particular variable need to be populated from two different variables.

In such scenarios , if we are using the BPEL Transformation activity , we need to make sure some dummy value is assigned to the variable in the .xslt file before the next assignment.

Consider a small scenario:

I need to populate  variable updateStudent, which comprises of

{
Student_No
Student_Name
Student_Age
Student_Mobile
Student_Address
Student_College
}

Out of these the i have all the values in my process input variable student_info , except Student_College.
I have the value of Student_College defined as a descriptor property in bpel.xml in 10g or composite.xml in 11g.

You can have a one on one mapping between student_info and updateStudent using an .xslt file.

You assign this value in another assign activity post the transformation.
But before using this we need to make sure we assign some dummy value to Student_College in the transform using setText.

 If we don't , the xslt engine will remove the element from the variable structure , and the next assignment activity will fail.