Is that you wanted updated selected records in table using updated records in file?
You cant make use of load utility directly
If size of the table is less unload it and compare with records in the file and create a fresh load file which needs to be present in the table and use LOAD replace
Or Compare the files and just check for the updated data and use programmatic method to update the table
Or Use Programmatic method to read and update the table ( If file has fewer records)
What you can do is ?
Split INSERT and UPDATE records into separate files, if possible.
Load the insert and Write a program to read the update file and update it in DB2.