Import subform data into one form and push to another form

Hi.

We have a user portal where:

the client receives spreadsheet template download after submitting details
client enters subform data into the spreadsheet, then imports the spreadsheet back into the same form's report.

We need the imported record and subform data to be transferred to another form where the data will be calculated and stored in CRM. (calculation and CRM integration script already completed)

We do it the is way because there is no way to filter the subform columns download that we don't want the client to see in the download of the main form's subforms.

We have a fetch and input script that works on manual user input in the "on success" part of the workflow, but not on import.

fet = Preferred_Partner_Sales_Form[ID == input.Preferred_Partner_Sales_Form_Link];
x = Preferred_Partner_Sales_Form.Cruise_Lines();
col = Collection();
for each rec in input.Cruise_Lines
{
x = Preferred_Supplier_Upload_Form.Cruise_Lines();
x.Cruise_Line_upload=input.Cruise_Lines.Cruise_Line_upload;
col.insert(x);
}
fet.Cruise_Lines.insert(col);

Please advise.

Thanks,

Jason