Small tip today, In one of my custom SSRS report for Dynamics Ax 2012 on group total, requires conditioning,
For example sum did not include the value in the based on certain value of other field.
I used following expression to solve this problem.
=Sum(iif(Fields!FieldName.Value <> “abcdxyz”, Fields!FieldName.Value, CDbl(0)))
I took help from following link: