selecting a range of package versions that my package depends on

[Marek Andrus <marek.andrus@wp.pl>]

Hi,

I used to work with portage and expected possibility to specify what 
particular version (or range of versions) of package my package depends 
on. I found sth like:
DEPENDS += "libgcrypt (>= 1.4.2)"
in gnutls.inc file. Unfortunately it doesn't work for me.
I found only one way to choose version of package: to add:
PREFERRED_VERSION_package = "versionstring"
to some global conf file like local.conf. In addition this method 
doesn't work with ranges (like >=1.15) or I don't know how...

I'm package maintainer so I don't want to add anything to files like 
local.conf, but I'd like to specify exact dependencies.

1. Is there any other way to choose what version of package should be 
chosen?
2. Is there any way to specify range of preferred versions?
3. Is there any way to specify what version (or range) my package 
depends on (not touching global conf files)?

Best Regards,
Marek