regex - Notepad++ find/replace for every value in a comma separated list -

i'm trying find values within comma separated list , replace them value.

for example, had following file:

{     letter: a, }, {     letter: b, }, {     letter: c, },

i have list "b, c". want make change every value within list. example:

{     letter: a, }, {     letter: b,     word: bat }, {     letter: c,     word: cat },

how go doing in notepad++? in advance!

ANy