[R] a replace for subset

[chalabi.elahe at yahoo.de]

Hi, 
I have a data set (mydata), which a part of this is like the following: 


'data.frame':   36190 obs. of 16 variables: 
$ RE                    : int  38 41 11 67 30 18 38 41 41 30 ... 
$ LU                     : int  4200 3330 530 4500 3000 1790 4700 3400 3640 4000 ... 
$ COUNTRY        : Factor w/ 4 levels "DE","FR","JP", "FR"… 
$Light                  : Factor w/2 levels   "ON","OFF","ON", …. 
$OR                     : Factor w/2 levels   "S","T","S",…. 
$PAT                  : Factor w/3 levels   "low", "high", "middle",…. 


Now I want to plot RE vs LU with ggplot2 for all the possible cases, I know how to do subsetting for the data but I want to know is there any shorter way to do that? For example I want to have a plot for RE vs LU for (COUNTRY= FR, Light=off, OR=S, PAT=low) and one for (COUNTRY= FR, Light=on, OR=S, PAT=high) and …., as you see doing subset is time consuming, is there any other way? 
Thank you for any help. 
Elahe