Mode line maker

mode-line-maker is a package to ease the creation of mode-line, header-line or tab-line. It allows to define the precise alignment of the mode-line (on left and right) and splits the mode-line into left and right parts, with automatic truncation (when there is too much information to display). It's available on ELPA.

Usage:

(require 'mode-line-maker)
(setq mode-line-format (mode-line-maker '("%b")
                                        '("%3c:%3l")))