You could use WMI to retrieve this (the text below can be copied/pasted into VBP). It will retrieve the entire command-line, including the executable.
<step action='Run Script' type='0'>
<Language>VBScript</Language>
<Script><![CDATA[Builder.LogMessage "VisBuildCmd command-line = '" & GetCommandLine & "'"
' use WMI to retrieve the command-line of the VisBuildCmd.exe
' process on the current machine (assumes only one running instance)
' see
http://msdn.microsoft.com/library/en...32_process.asp
' for more details
Function GetCommandLine()
Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonat e}!\\.\root\cimv2")
Set colProcesses = objWMIService.ExecQuery("Select * from Win32_Process Where Name = 'VisBuildCmd.exe'")
For Each objProcess in colProcesses
GetCommandLine = objProcess.CommandLine
Exit Function
Next
End Function
]]></Script>
<indent type='3'>1</indent>
<name>New Step</name>
</step>