combining several lines plots autmatically in one graph

[Jay Rege]

Sorry for the mass of questions today, but I´m pretty much under time pressure due to University Deadlines...
Following Problem: I want to combine all line plots of earnings belonging to a specific Group in one graph.
Lets say I have 200 Groups, each is defined by three key variables (Country, Age_group (5 categories), gender(dummy variable)(all three vraiables are string)).
I have longditudanal datapoints for all these Groups.
Now I want to combine the several Age gender Groups of one Country in one graph.
That means I want to create Age Gender Groups. The resulting 10 categories should be combined in one graph for each country
Since the dataset is pretty big I would like to use a Loop.
I´ve started with the following code

 egen Country_age_gender = group(Country Age_group gender)
egen Age_gender = group (Age_group gender)
encode Country, generate(country)
sum country
foreach i of num 1/`r(max)' {
   graph twoway line earnings

Here I don´t know how to include the several Groups in the line plot.
Thanks for your time, hoping the Problem is understandable

[Jorge Eduardo Perez Perez]

You can use levelsof and loop over the levels of the Country and age_gender variables. See help levelsof.