ScriptBlocks/DryAD_SB_RemoteWebCert_Export.ps1

Using NameSpace System.Management.Automation.Runspaces
# DryActiveDirectory is an AD config module for use with DryDeploy, or by itself.
#
# Copyright (C) 2021 Bjørn Henrik Formo (bjornhenrikformo@gmail.com)
# LICENSE: https://raw.githubusercontent.com/bjoernf73/DryActiveDirectory/main/LICENSE
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

[ScriptBlock]$DryAD_SB_RemoteWebCert_Export = {
    Param (
        [String] $Path,
        [Array]  $SignatureAlgorithms,
        [String] $KeyUsage
    )
    Try {
        $Cert = Get-ChildItem -Path Cert:\LocalMachine\My -ErrorAction Stop | Where-Object { 
            ($_.HasPrivateKey -eq $True) -and 
            ($_.SignatureAlgorithm.FriendlyName -in $SignatureAlgorithms) -and
            (@(($_.EnhancedKeyUsageList).FriendlyName) -contains $KeyUsage)  
        }

        # If multiple, use first
        If ($Cert -is [Array]) {
            $Cert = $Cert[0]
        }
        
        If ($Cert -is [System.Security.Cryptography.X509Certificates.X509Certificate2]) {
            Export-Certificate -Cert $Cert -FilePath $Path -Type CERT -Force -ErrorAction Stop | 
            Out-Null
        }
        Else {
            Throw "Certificate not found"
        }
        Return @($True,'')
    }
    Catch {
        Return @($False,"$($_.ToString())")
    }
}