Export-Csv
will always put all fields in double quotes, so you have to remove the undesired quotes the hard way. Something like this might work:
$csv = 'C:\path\to\your.csv'
(Get-Content $csv) -replace '^"(.*?)",(.*?),"(.*?)"$', '$1,$2,$3' |
Set-Content $csv
Regular expression breakdown:
^
and$
match the beginning and end of a string respectively (Get-Content
returns an array with the lines from the file)."(.*?)"
matches text between two double quotes and captures the match (without the double quotes) in a group.,(.*?),
matches text between two commas and captures the match (including double quotes) in a group.$1,$2,$3
replaces a matching string with the comma-separated first, second and third group from the match.