diff --git a/INFMaker.ps1 b/INFMaker.ps1
index b3a4252..df43585 100644
--- a/INFMaker.ps1
+++ b/INFMaker.ps1
@@ -1 +1,62 @@
-placeholder
\ No newline at end of file
+param(
+  [Parameter(Mandatory = $true)]
+  [string]$InputPath,
+
+  [Parameter(Mandatory = $false)]
+  [string]$OutputDir = (Get-Location).Path
+)
+
+if (-not (Test-Path -Path $InputPath -PathType Leaf)) {
+  throw "Input file not found: $InputPath"
+}
+
+if (-not (Test-Path -Path $OutputDir -PathType Container)) {
+  throw "Output directory not found: $OutputDir"
+}
+
+$template = @'
+[Version]
+Signature="$Windows NT$"
+[NewRequest]
+Subject = "CN=$Placeholder.printer.MBIE.govt.nz;OU=ICT;O=Ministry of Business, Innovation and Employment;L=Wellington;S=Wellington;C=NZ"
+X500NameFlags = 0x40000000
+Exportable = TRUE
+KeyLength = 2048
+KeySpec = 1
+KeyUsage = 0xA0
+MachineKeySet = True
+ProviderName = "Microsoft RSA SChannel Cryptographic Provider"
+HashAlgorithm = sha256
+RequestType = PKCS10
+FriendlyName = "$Placeholder.printer.MBIE.govt.nz - 2026"
+[EnhancedKeyUsageExtension]
+OID=1.3.6.1.5.5.7.3.1 ; Server Authentication
+OID=1.3.6.1.5.5.7.3.2 ; Client Authentication
+[Extensions]
+; If your client operating system is Windows Server 2008, Windows Server 2008 R2, Windows Vista, or Windows 7
+; SANs can be included in the Extensions section by using the following text format. Note 2.5.29.17 is the OID for a SAN extension.
+ 
+2.5.29.17 = "{text}"
+ 
+_continue_ = "dns=$Placeholder.printer.MBIE.govt.nz&"
+_continue_ = "dns=$Placeholder.wd.govt.nz&"
+_continue_ = "dns=$Placeholder.ciga.ldap.govt.nz&"
+_continue_ = "dns=$Placeholder.printer.MBIE.govt.nz&"
+_continue_ = "dns=$Placeholder.wd.govt.nz&"
+_continue_ = "dns=$Placeholder.ciga.ldap.govt.nz&"
+'@
+
+$invalidChars = [IO.Path]::GetInvalidFileNameChars()
+
+Get-Content -Path $InputPath | ForEach-Object {
+  $name = $_.Trim()
+  if ([string]::IsNullOrWhiteSpace($name)) { return }
+
+  $safeName = -join ($name.ToCharArray() | ForEach-Object {
+    if ($invalidChars -contains $_) { '_' } else { $_ }
+  })
+
+  $content = $template.Replace('$Placeholder', $name)
+  $outPath = Join-Path -Path $OutputDir -ChildPath ($safeName + '.inf')
+  Set-Content -Path $outPath -Value $content -Encoding ascii
+}