Report column for count of issues with custom field value

Hi all,

I am trying to add a column to a task report. It should be an integer, counting the number of issues within the task's project that have a specific value in a custom field. 

Problem is, there is not an equivalent for count(), and even len() is only applicable to text strings, not a collection (issues within a project). I can filter out the names of all the issues that have that status value, but I only need the count of objects, not the other properties of the objects.

Any suggestions? Thanks in advance.