How to import data from a fixed-length format file with double byte characters to E1

I tried to import data from a fixed-length format file which contains double byte characters to E1 Table using Table Conversion.

Since it is a fixed-length format file, I'm trying to find a way to count byte numbers to set data in the designed fields, but with TC,

I can only specify character length (not byte length) so I couldn't set data to the right fields if double byte character exists.  Is there any way to do that?