I think can only get the import status using the ImportAction Script.
You capture it in EndProcess sub event.
If you look at chapter 11 in the FDM API guide, you will see that at the point the file is imported, the FDM import process has not completed. Following the import there is the mapping and process logic steps amongst others. All the file import step does is load the data form the flat file into a temprary table. the following steps then perform the the mappings etc and load the data to the FDM data table. If you want to check the import status you need to select an event that occurs later in the import sequence, or as the previous repy states do it in the ImportAction script, but again at the appropriate point.
Did you finally manage it?