Hi,
You could use importdata to load csv files in matlab and identify the location of amplitude column using textdata string and the word amplitude. once you have identified the location of the column, you may simply use matlab vectorization, e.g., x(x(:,column_no)<10,column_no)=[]. note that, x can not be matrix as it may generates error.
if you could please provide me the csv files, i can simply do it for you. you may add several other options/tasks later to do...
thanks,
wahid