问一个简单的VB打开程序的问题

假设我有个N个程序
C:\1.exe, C:\2.exe, ……C:\N.exe
我要打开他们,但不是同时打开.
也就是说我打开1.exe,当1.exe运行完毕后,进程都没了的时候再打开2.exe,如何实现.

这个问题不是很简单了，呵呵。
Private Type STARTUPINFO
cb As Long
lpReserved As String
lpDesktop As String
lpTitle As String
dwX As Long
dwY As Long
dwXSize As Long
dwYSize As Long
dwXCountChars As Long
dwYCountChars As Long
dwFillAttribute As Long
dwFlags As Long
wShowWindow As Integer
cbReserved2 As Integer
lpReserved2 As Long
hStdInput As Long
hStdOutput As Long
hStdError As Long
End Type
Private Type PROCESS_INFORMATION
hProcess As Long
hThread As Long
dwProcessID As Long
dwThreadID As Long
End Type