Regular Expressions 101

Explanation
Pro

Group 1(<w:p[^>]+>(?:(?!<\/wp>).)+?<\/w:p>)

<w:pthe literal text <w:p (case sensitive)

Negated Character Class[^>]+

+matches at least one character outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Non-Capturing Group(?:(?!<\/wp>).)+?

+?repeats the group contents below at least once:

Negative Lookahead(?!<\/wp>)

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

wp>the literal text wp> (case sensitive)

.any character

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

w:p>the literal text w:p> (case sensitive)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

s modifier: single line. Allows a dot to match line terminators

Detailed match information will be displayed here automatically.

25 tokens

(<w:p[^>]+>(?:(?!<\/wp>).)+?<\/w:p>)

New

<w:p>
    Some Other XML
        <w:p someatribute="something">
        HERE
        </w:p>
    Some Other XML
</w:p>