Formula 1=SUM(OFFSET('Gross Pay'!$B$2,MATCH($B$1,'Gross Pay'!$B$2:$B$28,0)-1,1,1,MATCH($B$2,'Gross Pay'!$B$2:$N$2,0)-1))
Formula 2=SUM(INDEX('Gross Pay'!$B$2:$N$28,MATCH($B$1,'Gross Pay'!$B$2:$B$28,0),2):INDEX('Gross Pay'!$B$2:$N$28,MATCH($B$1,'Gross Pay'!$B$2:$B$28,0),MATCH($B$2,'Gross Pay'!$B$2:$N$2,0)))
Formula 3=SUM(INDIRECT(ADDRESS(MATCH($B$1,'Gross Pay'!$B$2:$B$28,0)+1,3,,,A5)):INDIRECT(ADDRESS(MATCH($B$1,'Gross Pay'!$B$2:$B$28,0)+1,MATCH($B$2,'Gross Pay'!$B$2:$N$2,0)+1,,,A5)))