As I've mentioned before, I use Microsoft Word to maintain the web site for a non-profit. To dip my toes into the waters of PayPal, I decided to go with the simplest option of adding "Buy Now" buttons to the site. To reduce concerns about people tweaking the information sent to PayPal, I decided to take advantage of PayPal's encyption option. I found that if I pasted the block of code from PayPal into the HTML editing window of Microsoft Word, Word would corrupt the block of code.
So now I keep two versions of the page in question: one with PayPal buttons, and one without. I use the one without buttons to edit everything in the page but the buttons using Microsoft Word. Where the buttons go, I enter the letters XX and YY.
Then, I make a copy of the page without buttons, and open the file using Notepad. Searching for XX and YY, I replace the letters with the blocks of encrypted code generated by PayPal. I then am careful not to open this file with Microsoft Word or else the code will be corrupted.
I keep the PayPal blocks of code in text files so that if I need to edit the pre-PayPal page using Word, I can do so and have quick access to paste the PayPal code in.