Large scale portfolio optimisation

I am new to MATLB and am slowly losing the will to live as the models and explanations are either complex or include downloading Dow Jones or NASDAQ data.

Is there a simple way to import data for 200 assets from Excel and to use MATLAB to create an optimised portfolio of 25-30 assets and their weightings.

Ideally in the UK environment as I do not want to download any USA data, nor do I need to see graphs of efficient frontiers etc