That is one approach. If it gives you what you need, great -- use it.
You also can do the individual steps CONVERT would do yourself if you want to make any changes to the names, datatypes, rearrange the columns, leave out some of the columns, etc.
You would create the table as you like, perhaps even editing the CREATE that CONVERT produced.
The SQLCI COPY or LOAD commands move data from Enscribe files to SQL tables. LOAD is faster, but deletes any existing data in the target table, so COPY should be used if you want to preserve existing data in the table.
You don't need a DDL record description if the Enscribe record layout matches the default layout SQLCI assumes for the table. That is documented in the SQL/MP Reference manual. It is pretty simple for most many column types, but there are a few tricky cases that are a little hard to understand. Or you can provide a DDL record description and SQLCI will do conversions between compatible Enscribe and SQL data types.
If you need the data in CSV format, you probably could do that with an ENFORM report, putting commas as literals in the print list, but my memory of ENFORM is kind of dim, and I don't have the spare time right now to look at it.
In case you don't know how to find the NonStop manuals, go to:
http://www.hp.com/go/nonstop-docs/
scroll down to the NonStop Technical Library part at the bottom of that page, and click on the link that names your system type (H-series, J-series, or G-series). The page that takes you to is a alphabetical list by manual title of all the NonStop manuals. Each manual title is the link to the PDF file that contains the manual.