[Edit : working with Quantum GIS version 2.0.1-Dufour]

I wonder if it is possible to use some field to set the symbology and some other to label the map.

[**Edit 1 :** I mean labeling the legend in the map designer tool to output as JPG or PDF, not labeling objects in the canvas for working purpose.]

[**Edit 2 :** The purpose of my question is to get an automatical process so I could save time and not manually change all the labels of the legend.]

My problem is : I have to make a map of natural habitats, based on european "CORINE biotopes" typology which uses entities with number and names, e.g. :

"37 hygrophilous meadows", 
"38 mesophilous meadows", 
"41 deciduous forests", 
"42 coniferous forests", 
"51 active bogs", 
etc.

So I would like to use shemes of the same color for habitats which are similar : all meadows in different tons of yellow, all forest in different tons of green, mires and bogs in some brown scale etc.

To do this I need to base my styling work on the NUMBERS, since following numbers identify similar habitats (meadows are 3X, forests are 4X, etc).

But for reading and understanding purpose, the printed map should be labelled with the NAMES. And the labelling should not get "noised" by the numbers, so I separated NAMES and NUMBER of the same entities in 2 different fields.

Is there some way to say QGIS to let me do the symbology on the basis of the "NUMBER"-field, but then to label the map on the basis of the "NAME"-field ?

I would like to set the "label" (like here from the Layer > Properties > Symbology)
![Layer - Properties - Symbology](https://i.stack.imgur.com/hAKCO.png)

To set the label of the legend in the Map Designer Tool : Here I would like to get the names of the habitats, and not the numbers.
![Map designer - Legend](https://i.stack.imgur.com/FzYF2.png)

Thanks for all kind of help.