If you have ever used the Windows Copy (Ctrl+C) to copy objects to the clipboard and then the Windows Paste (Ctrl+V) to copy/paste AutoCAD object(s), then you know that those clipboard object(s) will have the lower left-hand corner of their extents as the base point (not very precise)... and this always reminds me of some of the graphic editing applets (e.g.: Paint or even the wonderful AutoCAD Button Editor!) that have you draw a circle like a rectangle. (annoying to say the least!)
With AutoCAD you can use the keyboard shortcut of (Ctrl+Shft+C) to pick a base point for your clipboard object(s). COPYBASE is the actual command, and then you can paste to a precise point in the destination AutoCAD DWG file using the keyboard shortcut of (Ctrl+Shift+V). This is the PASTEBLOCK command or you can also use the PASTEORIG command if the COPYBASEd object(s) go in the same exact spot in the receiving DWG file.
Also it is important to note: If you do use the Ctrl+Shift+V PASTEBLOCK method and want to leave it as a block, AutoCAD will assign a name for the block, which is something like "A$C11A06AFD" or "A$C1F7A5022" ... Either use the RENAME command, or use EXPLODE or XPLODE, also watch your layers, with regards to the object(s) original layers and where this new "block" is being INSERTed... or where they go if they are EXPLODEd vs. XPLODEd. (I will save that for a whole different post).