You have made a slight mistake with your look-ahead syntax.

(?=pattern) Positive look-ahead match is followed by pattern
(?!pattern) Negative look-ahead match is not followed by pattern
(?<=pattern) Positive look-behind match is preceeded by pattern
(?<!pattern) Negative look-behind match is not preceeded by pattern

Note that for look-behind assertions the pattern can not be of variable width.

I hope this is of interest.

Cheers,

JohnGG

In reply to Re^2: Replacing exactly the found instance in REGEX by johngg
in thread Replacing exactly the found instance in REGEX by inquis

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