I looked around (Blogs, RTFM, usenet, etc...) for a doubt like this
but found no answer. So, I'd like to apologize first if this issue has
already being raised and answered. If so, please show me where it is.

I need to assign a task to each individual of a group in a way I can
follow up who did or did not the task. This taks must appear in the
individual task list of each member. Also, this cannot be a
"programmatically" solution.

E.G.: Like asking the group a task to remember them to fill out the
time report of the week.

I found how to assign a task to a group, however, any member of the
group can "take" the task and thus this task disappear from the group
list and this does not fulfill my needs.

Can you help me?

Regards