I'm working on AUTOCAD 2010 and Excel 2007 version. I'm not sure, but for me it looks more comfortable and automatic to use some executing button in an excel file than saving it as a .CSV file. I thought even it would be nice if excel in first step creates the layers (various thickness, colour and line types) and then in second step generates the lines combined with particular layers.

I'm grateful for your help Fixo.