I guess using a custom theme is your answer. I had asked a similar kind of question in past, the answer to that may help you, I am pasting the link to that post here: Custom Fields' Positioning on Sales Invoice - #2 by Tut
I guess using a custom theme is your answer. I had asked a similar kind of question in past, the answer to that may help you, I am pasting the link to that post here: Custom Fields' Positioning on Sales Invoice - #2 by Tut