How can I add leading zeroes to certain fields?

Looking for advice/insights:

Using Oracle Eloqua, I'm looking for a way to ADD a '0' to zip codes with 4 digital (US east coast zip codes), for example 2345 should be 02345

AND

add leading zeros to an ID field where the total character count should be 15, however, sometimes the leading zeros are stripped and we're left with 123 or 12356, so we'd need 123 to be: 000000000000123 and 12356 should be: 000000000012356

I was poking around in Regex replacement in the data washing machine activity but I wasn't able to find anything definitive.

anybody have any insights on how to accomplish this? THANKS! 🍩