Maintain formula "Links" when sheet moved

Is there a way to maintain established links when a work book is moved. I will have a cell formula that returns information from another workbook. Any time the workbook is moved or remnamed I have to manually update all the formulas. Is ther any way to lock this formula link. Example formula provided.

=SUMPRODUCT(('H:\MM_PLANNERS\Task Planning\OPR INFO\OPR DATA TRACKING\[1 HOURS WORKED TRACKING.xls]JAN 11'!$B$4:$B$5000="OT")*('H:\MM_PLANNERS\Task Planning\OPR INFO\OPR DATA TRACKING\[1 HOURS WORKED TRACKING.xls]JAN 11'!$L$4:$L$5000))