Hi,
I suppose you are importing multiple files to Origin with starting new columns for each file, right?
If so, you could try:

Then add the script in Script After All Files Imported:
//Add a new column
col(wks.nCols)[L]$= FileName;
int ncols = wks.ncols;
//Loop over every column
loop(ii, 1, ncols - 1)
{
//Put the content of SourceFile to the last column
col($(ncols))[$(ii)]$ = col($(ii))[D1]$;
}
Hope it helps.
Regards,
Yuki
OriginLab