matlab connect matrix

I created an L-Bend Structure using Matlab(by creating Nodes).I am using Finite element method to solve the equation(Laplace equation) to find the Potential V.I have split up the L-Bend into a 9 node structure marking the x,y coordinates(11,12,13,21,22,23,31,32,33).Now I have to write a mesh program to connect the matrix coordinates in matlab(using C).The element numbers have been marked within each finite element;the outer 1,2,3... are the global nodes and inner 1,2,3...(anti-clockwise direction) are the local nodes.I have attached the picture of the 9 node structure below.Please help me with the mesh program using C.[/b]