Getting value from CSV - powershell

Question

I'm writing a PowerShell script to read a CSV. I have everything working so far, it's able to find the value from user input (branch number) and finds the values that have "Y" in the available. Please see 2nd picture.
First picture is my CSV file.
This is what I need help with. How would I get the value of the first available CoreID? In this example, FMD354800000. Once I get the first available CoreId, I want to change the Available to N
$Find = $ImportCSV | Select-String -Pattern $GetBranchNum
$Find -match "Y"
New-ItemProperty -path $CoreIP -name "TTable ID" -PropertyType String -Value "Test" -Force

Answer 1

Use Import-Csv to import the CSV:
$csv = Import-Csv 'C:\path\to\your.csv'
Since the file seems to be fixed width you'll need to Trim() fields before checking their value.
$branchNumber = '8000'
$first = $csv | Where-Object {
$_.'Branch Number'.Trim() -eq $branchNumber -and
$_.Available.Trim() -eq 'y'
} | Select-Object -First 1
This filters the CSV for records with the given branch number that have a value Y in the field Available and selects the first matching record.
Then change the value of the Available field of that record:
$first.Available = 'N'
Demonstration:
PS C:\> $csv = Import-Csv 'C:\path\to\sample.csv'
PS C:\> $csv
Branch Number CoreID Available
------------- ------ ---------
8000 FMD354800000 Y
8000 FMD354800001 Y
8000 FMD354800002 N
PS C:\> $first = $csv | Where-Object {
>> $_.'Branch Number'.Trim() -eq '8000' -and
>> $_.Available.Trim() -eq 'y'
>> } | Select-Object -First 1
>>
PS C:\> $first
Branch Number CoreID Available
------------- ------ ---------
8000 FMD354800000 Y
PS C:\> $first.Available = 'N'
PS C:\> $first
Branch Number CoreID Available
------------- ------ ---------
8000 FMD354800000 N
PS C:\> $csv
Branch Number CoreID Available
------------- ------ ---------
8000 FMD354800000 N
8000 FMD354800001 Y
8000 FMD354800002 N
Neither Select-String nor the -match operator are particularly useful in this context, so don't use them.