need help with a simple code

this is what i want to do. say, i have three exe files that run three program. ex: a.exe, b.exe, c.exe. Now i want to show a screen, where there will be three button representing those three programs exe file. if the user press the "a" button, the a.exe will launch. any help on how to do it with code, will be helpful. all i need is instruction for one button, i will do the rest. Thanks. I am using Visual Basic 6 for this.
(i know this is very simple, but i have not been in touch with vb programming for a long time, so i can't do it)

private Sub Command1_Click()
Shell "c:\a.exe", vbNormalFocus
End Sub