[Gretl-users] Defining Panel Data

Hello All, I am ex-Stata user trying to work my way into gretl - though slowly. I have a panel data set in Excel for 56 state counties (identified by a unique county code 01 - 56) over 51 years (annual data 1990 - 2040). I seem to be able to load the data set into gretl and get it to recognize the panel nature of the data, but I can't seem to get it to acknowledge the labels for those years (i.e. 1990 - 2040) when using commands such as gnuplot for graphing. For example, when I load the data into gretl, it recognizes the panel as "Panel: Full range 1:01 - 56:51". When I restrict the full data set to say two counties and graph them (using "gnuplot County1 County2 -time-series -with-lines") the data are plotted on a graph with an x-axis scale from 1-51 instead of 1990 - 2040. How can I get it to recognize the data as that will create x-axis labels in -time-series graphs automatically with the respective dates rather than the periods 1 - 51? Thank you for your time on this! Joe