I am looking for a tool (if it exist) that given a chart from MS Excel return the LaTeX code to insert in a document.
I've used this workflow in the past for moving large numbers of graphs from Excel to a Latex document:
From Excel, print the chart to an .eps file format using a generic postscript printer device. In Latex, embed the .eps file.
Here's an online resource that has templates to get started: http://embedded.eecs.berkeley.edu/concurrency/latex/latexWithEPS.html