Adding pauses (, comma or # hash) to dial string?

[moapys]

Hi, I've not been successful in having my Echo Dot "understand" dial-string pause characters.  E.g.; in entering a conference call, how do we append the PIN/Conf-number to the bridge number itself?

I've tried following speaking the main number with the words, comma, hash, pause, wait, etc to no avail...  Is this, perhaps, a feature request?

Thanks!