Hello,
Here is another simple way of doing this without using scripts:
1) Select only baseline rows, for example by using the distribution of days and selecting baseline rows on chart.
2) Use Tables to create a subset table that includes only those rows. You may want to change the name of the column with baseline results.
3) Join the original table with the subset table so a new column with baseline results only wll be added to the original table with repeated baseline values for each subject.
4) Create a new column with a formula of change from baseline. This way different formulas can be easily tested (difference, ratio or %change from BL) and similarly applied to multiple parameters within the same table.
Takes a minute to do and is very flexible.