Redmine

Hi everyone

I have a project where i need one task to be fixed and the other to adapt "around" this task.

Example :

I have an important meeting on Jan. 1st and I know i can't change it.
I put the end and the beginning of this task on Jan. 1st

Now let say i have some paper to do, or some preparation for this task, like reserving a room, preparing my powerpoint etc...
right now, if i create one task "reserving a room" and i set a precede link between "reserving" and "meeting", the meeting is moved unless i'm totally right in the beginning and the end of my "reserving" task.

is there a way to say "meeting is at this date and no task can move it even if there is precede or follow link. If a task is suppose to move my meeting task, it will be this task that will change when it begins, not my meeting task"?

I hope i was clear enough for you to understand :/

Thanks for your help.