for %%I in (powershell.exe) do if "%%~$PATH:I" neq "" (
    set chooser_file=powershell "Add-Type -AssemblyName System.windows.forms|Out-Null;$f=New-Object System.Windows.Forms.OpenFileDialog;$f.InitialDirectory='';$f.Filter='Positive Registry Files (*.reg)||All Files (*.*)|*.*';$f.showHelp=$true;$f.ShowDialog()|Out-Null;$f.FileName"
)

for /f "delims=" %%I in ('%chooser_file%') do set "regfile=%%I"

C:DeployREG_DEPLOYPOS_regsSafe_YearSafe_Year.reg