I have a merge field in a tab delimited csv file that is of the format ["element 1", "element2"] from 0 to 12 elements.

What other information is required?



An example of the field in the csv would be <field separator tab>["element 1", "element2"]<field separator tab>

The VB function takes that data and format it into a multi line string but I now need to call that function and display that result in the merged document.

CSV files have Comma-Separated Values. A tab-delimited file is not a CSV file, no matter what extension you give it.
Evidently, then, you data are coming from some other system. You should get whoever produces the data to output in a format that is suitable for mailmerge. Alternatively, pre-process that data so it's suitable for mailmerge. That would require all 12 elements to be catered for in each record, even if empty.

Your ["element 1", "element2"], etc. do not constitute custom data types - in a tab-delimited file they are a single piece of data and, with the double-quotes, are liable to mess up a mailmerge.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]