exception handling with a conditional 'catch' using 'when' ???

Question - is there a construct in exception handling where a 'catch' can be conditional with a 'when' ?
e.g.,

try
{
...
}
catch when (condition1...)
{
....
}
catch when (condition2...)
{
....
}...
I know I saw some code somewhere (some blog) but can't seem to find it again... grr..