You can do a
find and replace:
Go into any offending cell in column D as if to edit it
Press the
Home key on the keyboard
Hold the
Shift key down while pressing the
right-arrow key (cursor key) on the keyboard once. Nothing will appear to happen. Persevere. Let go of the
Shift key.
Still on the key board press
Ctrl+c (to copy the character to the clipboard)
Select all the offending cells in column D
On the keyboard, press
Ctrl+h (brings up the
search and replace dialogue box) and click in the
Find what: field:
makes sure it's empty (press the
delete and
backspace keys a few times to ensure this) then
Ctrl+v to paste the character. Again, nothing will be apparent.
Click in the
Replace with: field and make sure it is completely empty. Other check boxes as below:

then click on
Replace All button.
Dismiss any message about how many replacements made and
Close the dialogue box.
Finished.
The leading character is unicode 8204, a non-joining zero-width character (hence you don't see it), possibly left over from a paste of values from a Chinese web site.