[Koha] Help to assign one barcode each to 10000+ records in mrc file

[Mrs. Chitralekha M. Chitale]

Sir, 

For the first time I purchased e-books from a publisher. They provided me a marc file (.mrc) for all the ebook titles (10000+). 
I can upload it directly to my Koha after adding and editing certain fields in records and add items with subfields having same description. 
I can do so using marcedit 5.2 as far as all records have same description to be added in that tag / copying from another field. 

But my problem is adding barcode (accession number in 952$p) to these records as each record will have different barcode. 

I tried converting marc file in excel. There is one marc tag per column but some of the columns have multiple subfields. 
I inserted barcode column, item type column, location column, Now I need to convert this excel to .mrc. 
The issue is I am not able to map them while converting to mrk file as each tag (above 010) must have subfield. 
I cannot map columns with multiple subfields eg. subject headings. 

Help me to assign one barcode each to these 10000+ records. 


Mrs. Chitralekha M. Chitale 
Librarian, Lokmanya Tilak College of Engineering, 
Navi Mumbai, India