Thanks for answering my question!
I understand your code and I know that we can use other structures to change the execution flow (including manipulating the stack)... I understand that if we change the return address written on the stack the execution flow will change to the address that was written on the stack. What I need to know is: is there any not unusual execution situation where the next instruction is not the one that follows the CALL? I mean, I would like to be sure that it doesn't happen, unless something unexpected occurs (like human intervention).
My concern is whether the commercial application programs in general, compiled by tools (in contrast to programs written directly in assembly by skilled programmers, like you) ALWAYS follow the mentioned pattern. Notice that in this case I have a fixation for exceptions (it is important to know whether they exist in this case, for a research project I'm developing into a M. Sc. program's discipline). I know, for example, that a compiler may, sometimes, change a RET to a JMP (tail-call optimization). I would like to know if something like this may change the order of the instruction that is executed after the RET and, mainly, if the CALL will always be just before the instruction executed after the RET.
Thanks again for your reply.