Well, I try to use it locate a string.
1) I run this, it works well.
2) Then I use the following one, it doesn’t work for me.
3) I tried to use the following one, it works.
I’m wondering if it’s a bug.
I don’t believe it is a bug. It is the specification of the regular expression EmEditor uses. The pattern in (?<=pattern) does not support vaiable length.