Create Multiple Entries From Each Row (truncating Rest Of Row)

I have a spreadsheet with 4 columns of information, then a column for a primary name, and then many columns of secondary names (with a different number of secondary names for each row).

For rows with more than 1 secondary name, I need to create a new row with a copy of all the columns up to the secondary name for each secondary name in the row.

A row in the spreadsheet looks like this:

data data data data PrimaryName SecondaryName1 SecondaryName2 SecondaryName3... SecondaryNameN

I need this row to be replaced by the following set of rows:

data data data data PrimaryName SecondaryName1

data data data data PrimaryName SecondaryName2

data data data data PrimaryName SecondaryName3
...
data data data data PrimaryName SecondaryNameN