Bulkloading xml's into Oracle table
As the ctl file can't be parameterized you'll have to create them for each infile.

As it is quite small, I'd create it on the fly from a here string with the format operator.

This sample script just echoes to screen, the commands to write/execute sqlldr are commented out.

## Q:\Test\2019\01\24\CR_212133.ps1
$dataFiles = @(
    "filelist21.dat"
    "filelist22.dat",
    "filelist23.dat",
    "filelist25.dat",
    "filelist121a.dat",
    "filelist121b.dat",
    "filelist122a.dat",
    "filelist122b.dat"
)

$ctlFile = "$PSScriptRoot\load_data.ctl"

foreach ($dataFile in $dataFiles) {
@'
load data
infile '{0}'
append
into table ogd_xml_table
fields
(
    filename FILLER CHAR(100),
    xml lobfile( filename) terminated by eof
)
'@ -f $dataFile  #| Out-File $ctlFile -Encoding ASCII
    #sqlldr mckdev@$SecretDatabase/$SecretPassword control=$ctlFile
}




&gt; Q:\Test\2019\01\24\CR_212133.ps1
load data
infile 'filelist21.dat'
append
into table ogd_xml_table
fields
(
    filename FILLER CHAR(100),
    xml lobfile( filename) terminated by eof
)
----------------------------------------------------------------------
load data
infile 'filelist22.dat'
append
into table ogd_xml_table
fields
(
    filename FILLER CHAR(100),
    xml lobfile( filename) terminated by eof
)
----------------------------------------------------------------------
%&lt;...snip...&gt;%