Word generally does an excellent job of deciding which way to "curl" the apostrophe, single quote, and double quote, but it appears to depend on the "adjacent space." A quote mark "preceded by a space and followed by a letter" will be a leftquote. A quote mark preceded by a letter (or .) will be a rightquote. If " you " put " spaces " on both sides, the result may be unpredictable, hence the need to proofread. (The "leading singlequote" on some tune titles may be a trouble spot?)

When you set the "use curlies" the keystroke inserts a straight quote, and it's autocorrect that replaces it with the left/right curly, so when you tell it to search for " it finds them all. If you want to search only for a single one of the curly marks you need to use "Find ^0145" for ‘, "Find ^0146" for ’, Find ^0147" for “, "Find ^0148" for ”, "Find ^0034" for ", and "Find ^0039" for '.

Incidental info is that Word sorts (Table|Sort) more or less by ANSI value, so if you're using curly quotes and paste something with straight quotes in, lines/fields that begin with a quote will be split into two separate places in the sort order. You need to do the (Replace " With ") and (Replace ' With ') things to get them all the same before sorting - if it matters.

John