I explained how to use it in the first line.
but simply, if the field number is 11 your code would be (raw code)
<php>$formatted = str_replace('{content}',$member['field_11'],$this->caches['profilefields'][11]['pf_topic_format']); $formatted = str_replace('{title}',$this->caches['profilefields'][11]['pf_title'],$formatted);</php>
then use {$formatted} to show the formatted string . Remember this will only work when you have a field that was formatted in the creation of the custom profile fields.
Tho I thought the whole purpose was for you to use your own customized code.