Trying to give the MICR a fixed position in the check form

The Payee name and address are just above the MICR on the check, and we recently found that vendors with 4 address lines will cause the MICR to be pushed too low on the form, sometimes on the next page.  In the template the MICR is maybe .5 inches from the lower page margin.  How can I make it stick there regardless of whether the last address line is used?  Note that the last address line is far north of the MICR so there is room on the page for both the address and the MICR line.  Seems like there