How to plot only variables selected by a user in GUI?

I am creating a GUI which after pushbutton1 will load the data which is stored in handles as a structure. There are 10 variables available (stored as a field) and data and time is stored as different fields in this structure. I would like to create a list which will allow user to choose up to 5 variables from the list and then plot then variables (from data) against time. I have created a list with strings, but I am not sure how to connect that string to the variables names and the actual columns in the dataset:

list = {'varname1','varname2',..., 'varname10' };

[indx,tf] = listdlg('ListString',list);

Also how to update that list with those that has been chosen? (I was thinking of a list that is ''dynaically'' changed once the user has selected the variables.)

[Stephen23]

@Wiktoria Glogowska: if you want a more dynamic GUI then perhaps a simpler approach would be to have five drop-down menus (i.e. uicontrol) which the user can select from, and then simply update the plot within the callback of each drop-down menu. That way you could easily use handles and indices very neatly to keep simply update the line data.