generating random nodes on a constraint area in playground !

[Mohammad Roshan]

Dear all,

I'm trying to use a part of omnet playground as a simple intersection,in other words I need to define an intersection (constraint area) on the playground and generate random number of nodes and place them only on the intersection (constraint area) lines.

Suppose that I have a (3000m*3000m) playground and want to place the intersection point of x and y axis at (1500m,1500m),exactly at the middle point of the ground,

I need to know;

1. How to define such a cross on playground at run time? 

2. Which command can help to generate random nodes and place them in different positions at each running?

any quick idea or experience can help a lot and appreciate in advance.

Regards.