So,if I understood well, you know the relative location of said hole measured from one corner of the block. You have (at least) three options:
- Place the UCS to a face and from there input the coordinates of hole's center - keep in mind that the corner where you placed the UCS is the new origin. May be useful in this case to display the USC in his current location.
- Create the hole (to be precise, the cylinder you want to extract as hole) in the corner of the block and call next the MOVE command to locate it at the desired location - use relative coordinates for this (@).
- Use the From command modifier; just press <Ctrl> + right click and chose it from contextual menu; next indicate the corner of the block and input the dispacement to hole's center - dont forget that require relative coordinates (@)