My Excel is in French so perhaps the English version on the menu bar is a little different. I've translated the option reference, but I think you'll find the option good.
Instead of using the import function of Client Access directly from the emulator, you can import from Excel and you'll have the fields texts also. If you don't already have the import function on MS Excel (menu bar option data), you can add it in 4 steps.
1. Note the path to Client Access
2. Run "regedit"
3. Under regedit find the key "Microsoft Excel" you'll find several, but we must be interested in the keys with the final path of "ExcelMicrosoft Excel".
4. For each correct key, create a new string value "OPEN" update the value by : /R "
You can now import data from the AS/400.