icalevent.detail_body and additional php-code

Hello experts,

I do syncronize some events from a google calendar and so it is not possible for me to give these events some additonal customfields.
Now I want to show some additional information at the icalevent.detail_body, depending on the event-title.

Something like...
If the title contains the word "kidsclub", show the information "until age of 7 years" at position "xy"

Is it somehow possible to do this?

I think it would be much better to make an override of icalevent.detail_body .php but I don't know how.

....and this override should only be shown at one category. :-)

regards,
Berndi