Dynamic changing values at a GtkTreeStore with pointers

["Diogo Ramos" <diogofsr gmail com>]

Hello to everybody,

This question is cracking my head off. I am days at it and i can't figure it out, although I thing a got pretty close.
Here is the deal:
I have a GtkTreeStore that I use to show some values.
This values can be changed.
So, my idea is to store a pointer at a cell so, every time I change the value of my data, the data is changed at the GtkTreeStore throw the pointer.
I don't know if it's possible, but I am trying, :-)
My last idea was change the GtkCellRendererText using gtk_tree_view_column_set_cell_data_func so, every time the render is called, a function of mine would translate a pointer, which is stored in the tree, to a text. But it didn't work. It wont stop complaining. 
Here is the menssage: GLib-GObject-WARNING **: unable to set property `text' of type `gchararray' from value of type `gpointer'
I think it's because I set G_TYPE_POINTER at the model but the render I am using is for text, although I change the value when It has to be rendered.

Someone knows how to accomplish that or, at least, if it is ever possible to do?

Thank you,
Diogo