How can I convert a time duration in time stamp format to a single integer representing seconds?

I have a data set that has a column for call duration. It is in "timestamp" format. For example, a 16 minutes and 35 seconds duration shows up as 0:16:35. Is there a way to convert this column to a single integer representing the number of seconds. For example, in this case I would need 0:16:35 to be 995. Is this possible to do within the magic etl environment? I would like for this method to be reproducible for other users that may not necessarily be expert coders.