How can I run a a Powershell command in VBA which contains "$env:UserName"? - vba

Question

I have the following macro which works just fine:
Private Sub Macro()
Dim ExecuteCommand As String
ExecuteCommand = "PowerShell -Command ""& 'C:\Program Files\R\R-4.2.2\bin\Rscript.exe' 'C:\Users\MyUser\Cool Calculations.R'"""
Shell ExecuteCommand
End Sub
What I want to do however, is to replace the name "MyUser" with $env:UserName instead.
However this macro does not seem to work:
Private Sub Macro()
Dim ExecuteCommand As String
ExecuteCommand = "PowerShell -Command ""& 'C:\Program Files\R\R-4.2.2\bin\Rscript.exe' 'C:\Users\$env:UserName\Cool Calculations.R'"""
Shell ExecuteCommand
End Sub
I have tried to run the command manually in PowerShell and it works correctly:
& "C:\Program Files\R\R-4.2.2\bin\Rscript.exe" "C:\Users\$env:UserName\Cool Calculations.R"
I am not sure what I am doing wrong when trying to add $env:UserName in my macro?

Answer 1

As Mathias points out, only "..." strings (expandable strings) perform variable expansion (interpolation) in Powershell; '...' strings (verbatim strings) do not.
Thus you must pass what PowerShell ultimately see as a "C:\Users\$env:UserName\Cool Calculations.R" argument (as an aside: consider simplifying to "$env:USERPROFILE\Cool Calculations.R"); since you're calling from VBA, this requires:
Using ""..."" to embed " chars. inside a VBA "..." string...
and \-escaping for the sake of powershell.exe, the Windows PowerShell CLI (which receives its -Command argument as a "..." string, so any " chars. to be retained as part of the command must be escaped)
That is, you need something like the following (sic; spaces added for readability)
" PowerShell -Command "" & '...' \""...\"" "" "
Specifically:
Private Sub Macro()
Dim ExecuteCommand As String
ExecuteCommand = "PowerShell -Command ""& 'C:\Program Files\R\R-4.2.2\bin\Rscript.exe' \""C:\Users\$env:UserName\Cool Calculations.R\"""""
Shell ExecuteCommand
End Sub

Answer 2

mklement0's response is very elegant, tested working. But I tested the command without escape, that seems not required under Windows Powershell, as Mathias suggested, it works also. I replaced Rscript.exe that I have not installed, by Get-ChildItem cmdlet like this:
Sub RunPSFromVba()
Dim ExecuteCommand As String
'ExecuteCommand = "PowerShell -Command ""& 'C:\Program Files\R\R-4.2.2\bin\Rscript.exe' 'C:\Users\$env:UserName\Cool Calculations.R'"""
ExecuteCommand = "PowerShell -NoExit -Command ""& 'Get-ChildItem' ""C:\Users\$env:UserName\Downloads"""""
Shell ExecuteCommand
End Sub
With PowerShell -NoExit, I keep the PowerShell Window alive after execution, I got this screenshot:
Hope this will also help.