Creating a script to take the medain of a row across multiple columns?

Hello -
I am new to IDEA, and was hoping someone could assist me.  I have files in a similar format as below.  What I need to do is take the median of Amt1 - Amt5 for each value in the Text column.  I created the median field using the excel function and was hoping I would be able to do the same in IDEA.
I've been able to compute the median for individual columns, but have not yet figured out a way to do it across a row.
Thank you in advance.