Generate a ds9 circle region line.

ds9circle 150.0 100.0 16.0 green 3 
arg1 - Xo of circle 
arg2 - Yo of circle
arg3 - radius of circle 
arg4 - color 
arg5 - text string 

In a script:
ds9circle  50.0 300.0 16.0 green 7 >>gen2.reg