The bracket is say, 15 X 2 and I want the circle 5/8 from the end and centered top to bottom.
Welcome to the forum,
After drawing the rectangle my approach was:
1. Click on the Circle Centre and point tool
2. Move the cursor over the line at the end of the rectangle where the circle is to be located.
3. Press the 'M' key which will activate a single midpoint SNAP, enter the size of the circle required in the Inspector Bar at the bottom of the scree.
4. Click on the circle to highlight it, in the Delta 'X' field on the Inspector bar ENTER -5/8" to relocate it.