I think u guys have misunderstood the question. I dont use Edison but im pretty sure the op means he wants to highlight a section of a sample, and take the actual highlight marker and move it over to another part of the song hes sampling so he can chop out another sample exactly the same length as the first, kinda like using a cookie cutter to stamp out exactly the same length every time, but i might be wrong. In Audacity the way i do this is i use the Time Shift tool to move the waveform left and right and it keeps my selection marker the same, maybe try looking for that in Edison, the button looks like this in Audacity "<->".