Matching whole words in find/replace script

[greektranslator]

On the C:/Temp/Substitutions.txt file I have a list of words separated by space. I want to match a whole word on the left, and replace it with the whole word on the right of the list. For example, if in my substitutions file there is

comp [[comp]]

I do not want it to match words like

computer
uncompare

but only instances of the word "comp" (the word may be preceded and followed by punctuation of course).