string files = "file_1%(CRLF)file_10%(CRLF)file_2";
int n = files.GetNumTokens(CRLF);
Dataset ids;
ids.SetSize(n);
for (int i = 1; i <= n; i++) {
	string file = files.GetToken(i, CRLF)$;
	string strFileIndex = file.GetToken(2, '_')$;
	int index = strFileIndex.value();
	ids[i] = index;
}
ids = sort(ids);
for (int i = 1; i <= n; i++) {
	string file = "file_$(ids[i])";
	type %(file$); 
}

@echo off
SETLOCAL EnableDelayedExpansion
for %%f in (file_?.) do (
set _fff=%%f
ren !_fff! !_fff:~0,5!0!_fff:~5!
)