This will do,

Compare.sh
#!/bin/sh
#cut column 3 from FileA and put it to FileA.tmp
cat FileA | cut -f3 -d";" > FileA.tmp
#cut column 4 from FileB and put it to FileB.tmp
cat FileB | cut -f4 -d";" > FileB.tmp
#compare FileA.tmp and FileB.tmp
diff FileA.tmp FileB.tmp
rm FileA.tmp FileB.tmp

sh Compare.sh
2a3
> d
4,5d4
< f
< q

-Om