I would like the code to automatically function when the page loads... the above Macro

=IFERROR((INDEX(O7:AH19,,MATCH(AI$2,V$4:AH$4,0))-INDEX(O7:AH19,,MATCH(AI$2,V$4:AH$4,0)-1))/INDEX(O7:AH19,,MATCH(AI$2,O$4:AH$4,0)-1),"")
is loaded into each cell in the column...