From the Actions Dropdown > Format > Compute you can create new custom columns. This can be done by adding specific computations to ICEFLO. In the example below we are going to add a new column to identify when a task has an external dependency.

In the Column Heading Cell, name the new column. 

In the computation cell add the computation which needs to be run in order for the information to be calculated. 

On hitting apply the new column which you have computed will be showing on the list tasks view.