Bulk create Active Directory Users and Groups in PowerShell using Excel XLSX source file instead of CSV

Hi Scripting Guy.  I am a Server Administrator who is very familiar with Active Directory, but new to PowerShell.  Like many SysAdmins, I often need to create multiple accounts (ranging from 3-200) and add them multiple groups (ranging from 1 - 100).  Previously I used VBS scripts in conjunction with an Excel .XLS file (not CSV file).  Since VBS is essentially out the door and PowerShell is in - I am having to re-create everthing.

I have written a PowerShell script that bulk creates my users and adds them to their corresponding groups - however, this can only use a CSV file (NOT an XLS file).  I understand that "CSV is much easier to use than Excel worksheets", but most times I have three sets of nearly identical groups (for Dev, QA and Prod).  Performing Search and Replace on the Excel template across all four Worksheets ensures the names used are consistent throughout the three environments.

I know each Excel Worksheet can be exported as a separate CSV file and then use the PowerShell scripts as is, but since I am not the only SysAdmin who will be using these it leads to "unnecessary time lost", not to mention the reality that even though you clearly state "These tabs need to be exported using this naming standard" (to work with the PowerShell scripts) that is not the result.

I've been tasked to find a way to modify my existing PowerShell/CSV scripts to work with Excel spreadsheets/workbooks instead - with no success.  I have run across many articles/forums/scirpts that let you update Excel or export AD data into an Excel spreadsheet (even specifying the worksheet, column and row) - but nothing for what I am trying to do.

I can't imagine that I am the ONLY person who is in this situation/has this need.  So, I am hoping you can help.  How do I modify my existing scripts to reference "use this Excel spreadsheet, and this specific worksheet in the spreadsheet prior to performing the New-ADUser/Add-ADGroupMember commands".

For reference, I am including Worksheet/Column names of my Excel Spreadsheet Template as well as the first part of my PowerShell script.  M-A-N-Y T-H-A-N-K-S in advance.

   Worksheet:  Accounts
     Columns: samAccountName, CN_DisplayName_Name, sn_LastName, givenName_FirstName, Password, Description, TargetOU

   Worksheets:  DevGroups / QAGroups / ProdGroups
     Columns:  GroupName, Members, MemberOf, Description, TargetOU

#	Load PowerShell Active Directory module
 Write-Host "Loading Active Directory PowerShell module." -foregroundcolor DarkCyan # -backgroundcolor Black
 Import-Module ActiveDirectory
 Write-Host " "
#	Set parameter for location of CSV file (so source file only needs to be listed once). 
$path = ".\CreateNewUsers-CSV.csv"
#	Import CSV file as data source for remaining script. 
$csv = Import-Csv -path $path | ForEach-Object {
	# Add '@saccounty.net' suffix to samAccountName for UserPrincipalName
		$userPrincinpal = $_."samAccountName" + "@saccounty.net"
	# Create and configure new AD User Account based on information from the CSV source file.
		Write-Host " "
		Write-Host " "
		Write-Host "Creating and configuring new user account from the CSV source file." -foregroundcolor Cyan # -backgroundcolor Black
		New-ADUser -Name $_."cn_DisplayName_Name" `
		 -Path $_."TargetOU" `
		 -DisplayName $_."cn_DisplayName_Name" `
		 -GivenName  $_."givenName_FirstName" `
		 -SurName  $_."sn_LastName" `
		 -SamAccountName  $_."samAccountName" `
		 -UserPrincipalName  $userPrincinpal `