Table Cycling for Powershell - powershell

Question

I'm creating a powershell script that I want to read a value (VALUE1) from an excel table (I can convert it to XML if necessary), assign it to a variable($PLACEHOLDER), run the rest of the script, then loop back to the beginning, but instead of reading the original value(VALUE1) I want it to read the value below it(VALUE2) and overwrite $PLACEHOLDER with VALUE2, then re-run the script until it returns a blank value, then I want it to stop. I am insanely new to powershell and it's interaction with excel/xml, so any help would be greatly appreciated. (I'm self-taught, so I don't know TOO much about parameters)
Sample in Terrible Psuedo:
#Initial placeholder value here
$RowNumber = 0
#Start of the loop here, add one to previous value
$RowNumber +1
#Call the value in Column (1), Row ($RowNumber), and assign it to $RowValue
?????? = $RowValue
#Execute the command involving the data value
ECHO "C:/test/temporary/$RowValue"
#Goto the start of the loop.
If you could be so kind, would you please give a quick explanation of the functions that you use (Parameters, what's happening, ect.)
EDIT: If it could detect and skip over blank rows, that would be amazing.
EDIT3: Code for Ansgar
$xl = New-Object -COM 'Excel.Application'
$xl.Visible = $true # set to $false for production
$wb = $xl.Workbooks.Open("C:\Documents and Settings\xe474109\Desktop\EXCEL FILES\testbook2.xlsx")
$ws = $wb.Sheets.Item(1)
$row = $ws.UsedRange.Rows.Count
while ( $ws.Cells.Item($row, 1).Value -ne $null ) {
$PLACEHOLDER = $ws.Cells.Item($row, 1).Value
#
# do stuff with $PLACEHOLDER here
#(I wanted to test this by just printing the $PLACEHOLDER value
$PLACEHOLDER
$row++
}
$wb.Close()
$xl.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($xl)

Answer 1

Do you have Excel installed? If so, you can process Excel spreadsheets like this:
$xl = New-Object -COM 'Excel.Application'
$xl.Visible = $true # set to $false for production
$wb = $xl.Workbooks.Open('C:\path\to\your.xlsx')
$ws = $wb.Sheets.Item(1)
$row = $ws.UsedRange.Row
while ( $ws.Cells.Item($row, 1).Value -ne $null ) {
$PLACEHOLDER = $ws.Cells.Item($row, 1).Value
#
# do stuff with $PLACEHOLDER here
#
$row++
}
$wb.Close()
$xl.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($xl)

Answer 2

cls
$csv = Import-csv -Path 'C:\test\csvStuff.csv'
foreach ($rec in $csv) {
if ($rec.nameofyourcolumn -ne '') {
& "c:\test\temporary\$($rec.nameofyourcolumn)"
}
}