Creating a dynamic plotter on the gui

I have a struct of data which basically has a a data name (like Task A, Task B, etc) and each name corresponds to a data set with varying number of columns. Within a task the number of data points remains constant across all columns though. The headers for these columns are consistent across my structure and those are found in another array let's call Headers. What I am trying to do is build a 3 column table on my gui:

    Lists the Task Names
    Lists the headers
    Lists the Headers again

all items have a check box associated with them and the user can select what data to plot against what. like Task A data, (header A, header C), or any combination of the data they choose.

I have been trying to follow this example, found here http://stackoverflow.com/questions/28607322/have-a-list-of-strings-i-want-to-populate-a-gui-with but am having trouble referencing the struct properly and getting everything organized as far as coordinating what to reference when. examples of my struct, the data within the structure and the headers cell array are in the attached data file. testfile.mat.