PHP在范围之间最后出现（strrpos）

How could i get last occurrence of symbol between some range ?

strrpos($text, '.', 100) it gives me last occurrence starting from 100 to the end

but how get last occurrence between some range, like:

strrpos($text, '.', 100-250) ?

This would work:

strrpos(substr($text', 100, 250), '.');

You can use a mix with strrpos and substr like strrpos(substr($text, 100, 250), '.')