I am getting error DIV/0. I know I need to use the ISERROR function,
however I'm not sure where to insert it. The formula I am using is
below. I know I will have cell divided by Zero and want to keep it
that way. But I don't want the DIV/0 to appear and I don't want to
white it out either.

=IF(SUM($K57:Y57)=$J57,0,IF(Z$1=$I57,($J57-
SUM($K57:Y57))*HLOOKUP($H57+Z$1-$I57,INP2006,$G57,FALSE)/
SUM(INDIRECT(CONCATENATE("'",$F57,"'","!",HLOOKUP( $H57+Z$1-
$I57,INP2006,2,FALSE),$G57)):INDIRECT(CONCATENATE( "'",
$F57,"'","!",HLOOKUP(HLOOKUP(10000,INP2006,1,TRUE) ,INP2006,2,FALSE),
$G57))),""))