The code I provided looks like it sticks to the selection so I'm not sure why it is failing for you.

Is the first/last character in your selection one of the found items?

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Andrew Lockton
Chrysalis Design, Melbourne Australia

If the found item is the first character of the selection then wdreplaceall replaces beyond the selection if the found item is other than the first character then the code works fine and only replaces within the selection.