Thank you for getting back to me. I will try to explain. I load .tdm file with over 100 group channels. 2 channels within all the channels I load are Temperature and Mass (same length), I would like then load 3d look up table which has got Temperature, Mass and factor. So what I need is script which will go trough this two channels (Temperature and Mass in .tdm) and look at the first values, lets say first value is 85degC and corresponding 1000g, it will look in the excel table loaded and check what the factor is at 85 degC and 1000g, than it takes the factor lets say it will be 0.2 and multiply the Mass with it and saves result in new channel.