Conversion of vcf files to nfb file format

The only way how contacts in vCard format (.vcf) could be "converted" to a .nfb Nokia backup, would be to first sync or otherwise import the contacts to the Nokia device and then perform a full phone backup using Nokia software, which would generate an .nbf file. It is not actually conversion in the traditional sense, more of a workaround how to achieve contacts backup.

Open VCF file    Open NFB file