Total amount of efforts estimates per file

[dkrm]

Hi,

I have a per-project workflow, where each file is a project and every top 
headlines is a task in the project. At the beginning of a project I create the 
tasks for it and add an effort to each tasks. Then I want to have the sum of 
the efforts for the whole project. At this time there is no clocked time yet 
so, unfortunately, a clocktable doesn't work.

The closest that I could get was to create a 'columnview' dynamic block. With 
this Org file:

* NEXT task1
:PROPERTIES:
:Effort:   0:10
:END:
* NEXT task2
:PROPERTIES:
:EFFORT:   4:30
:END:
** NEXT subtask2-1
:PROPERTIES:
:Effort:   3:00
:END:
** NEXT subtask2-2
:PROPERTIES:
:Effort:   1:30
:END:
* NEXT task3
** NEXT subtask3-1
* NEXT task4

The columnview dynamic block produces this:

#+BEGIN: columnview :hlines 1 :id global :format "%50ITEM(Task) %Effort{:}"
| Task       | Effort |
|------------+--------|
| task1      |   0:10 |
|------------+--------|
| task2      |   4:30 |
| subtask2-1 |   3:00 |
| subtask2-2 |   1:30 |
|------------+--------|
| task3      |        |
| subtask3-1 |        |
|------------+--------|
| task4      |        |

But the efforts total is not calculated. Is there a way to get it?