sh-2.02$ w=/usr/share/dict/words
sh-2.02$ sed -n /^[a-e].*xy$/p $w
apoplexy
boxy
carboxy
epitaxy
epoxy
sh-2.02$ grep ^[a-e].*xy$ $w | sed s/p/m/
amoplexy
boxy
carboxy
emitaxy
emoxy
sh-2.02$ grep ^[a-e].*xy$ $w | sed s/p/m/g
amomlexy
boxy
carboxy
emitaxy
emoxy
sh-2.02$ sed -n /^[a-e].*xy$/s/p/m/gp $w
amomlexy
emitaxy
emoxy