You will need to know what timezone the time is in before you can complete this.
Assuming the time is in GMT:
20180802 and 1352 are very close to how Pega natively stores its timestamps. Turn this into a single string "20180802T135200.000 GMT" and set this value to a property of type DateTime in your Pega page.
It is important to know the timezone of the time you receive as Pega will want to manage it in the GMT timezone.
Once on the clipboard as a Pega DateTime property, a field on your Section rule bound to the Date Time property provides options on the date/time format to display that timestamp as. Pega will also display the date/time according to the timezone of the current user, as per the TimeZone value on their Operator ID.
Using your proposed format, a user in US East Coast would see the time shown as: