Building Debian package on special location

Dear couchbase users, developpers,

I’m currently trying to build couchbase on my Debian installation. I would like to install it on different location (/etc /var /usr) instead of all in /opt.

I did manage to build the package and to put files in the wanted place.

Example :

But the configuration inside are wrong, example :
{path_config_tmpdir, “/my_packaging_directory/install/var/lib/couchbase/tmp”}.
instead of :
{path_config_tmpdir, “/var/lib/couchbase/tmp”}.

Does someone already tried to do so ? And did you manage to change the path properly ?
Maybe with fakeroot or somthing like that ?

PS : I use couchbase 2.2.0, community edition.

Thanks for help,