constructing a boundry matrix after using "pdebound", user defined function

Hi, i worte a user defined function for the construction of the boundary conditions. the output of this function is 4 different matrices instead of one boundary condition matrix which is needed in order to use the "assempde" function for solving the pde problem. is there a way to assemble one boundary matrix from those 4 matrices (H, R, Q, G) or does the "assempde" can work with those four separetly?

thank you