We have multiple templates ready in ZebraDesigner and saved as *.nlbl files - i.e. with placholder textboxes and barcodes all in the correct locations / sizes etc

We need to use .net to open this *.nlbl files, populate the placeholder textboxes and barcodes with real data then save as a zpl file.

Stackoverflow and general googling gives a barrage of outdated / conflicting information on this topic.

Please can you confirm the "pest practice" way for us to acheive the above? Is there an SDK that will open an nlbl file and allow the export to zpl file?