Write a VBA code to implement Gauss-Seidel iteration method, then use the code to solve a 4 x 4 system of equations represented by following augmented matrix:

10	3	1	5	-10
2	10	1	3	18
4	2	15	1	-18
-3	1	3	12	17

Try to use 0 as the initial trial values for all x. After iteration gets converged, return the solution to spreadsheet.