When dealing with the MARC Leader, 008, and other fixed length control fields, it would be nice to be able to make the modification templates look at, match on, and alter only a specific position or range. 

For example, suppose I have several records in which I want to change the 008 position 33 (Literary form) from a 0 to a 1 (nonfiction to fiction).
Currently I could tell my modification template to update the 008 of every record I point it at where the character in position 33 is a 0 (using regex to match only that specific character). But then there's no way to change ONLY that character and preserve the rest of the field.