Vista or later
If you are on Windows Vista or later, it will come with PowerShell. The PowerShell one-liner
(New-Object -ComObject "Shell.Application").FileRun() will work.
You can run this directly from the legacy command line (or within a batch file) with the following:
powershell -c (New-Object -ComObject "Shell.Application").FileRun()
This is an adaptation of the VBScript command outlined below.
For older versions of Windows (this will also work in newer versions, but requires an additional file), you can do this via VBScript, using the Shell object:
dim oShell = CreateObject("shell.application")
Shrinking it into one line:
Simple put that line into its own plain text file and save it with the extension
ShowRunDialog.vbs. Then run
ShowRunDialog.vbs from the command line.
This indirectly runs the
RunFileDlg function contained within
shell32.dll. See here.