You can simply reference groups > 9 in the same way as those < 10
i.e $10 is the tenth group.
For (naive) example:
String:
abcdefghijklmnopqrstuvwxyz
Regex find:
(?:a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)(m)(n)(o)(p)
Replace:
$10
Result:
kqrstuvwxyz
My test was performed in Notepad++ v6.1.2 and gave the result I expected.
Update: This still works as of v7.5.6
SarcasticSully resurrected this to ask the question:
“What if you want to replace with the 1st group followed by the character ‘0’?”
To do this change the replace to:
$1\x30
Which is replacing with group 1 and the hex character 30 – which is a 0 in ascii.