remapping whole namespace in launchfile

edit

Let's say I have a node with several topics like this:

/group/node/topic1
/group/node/topic2
/group/node/topic3
...

Now I want to remap all topics to a different namespace like this:

/important_topics/topic1
/important_topics/topic2
/important_topics/topic2
...

Is there an easy way to do this in a launchfile without remapping every single topic? For example something like this:

<remap from="/group/node/" to="/important_topics/" />