Only use Trokil's suggestion in the most formal situations.
and even then... it really sounds like a line from a theater play or en epic old movie,
the subjunktiv forms of many verbs are far more in use than that of the verb tun
dafür bräuchte ich...
ich fände is super wenn..
es gäbe eine Möglichkeit (or) es bestünde eine Möglichkeit...
all those you can hear them around but
"es täte mir leid" I haven't heard anyone use it here, quite frankly