Case sensitive string replacement in Eclipse or Notepad++

np++ regex is very poor, you can use a perl one-liner to do the job:

perl -pi.back -e's{(productmember)}{ uc fundmember | (uc $1 ^ $1) . (uc(substr $1, -1) ^ substr $1, -1) x (length($new) - length $1) }egi;' theFile

Extracted from perl faq6

In eclipse you can use the regex retain-case operator: \C. To solve your example you should search for "Product", replace with "\CFund" (be sure to tick the Regular expression option). This will replace Product with Fund and product with fund.

Update:

Make sure not to have the Case Sensitive box checked.