In the declarations section of your code, add:

Public Declare Function ShellExecute _
	Lib "shell32.dll" _
	Alias "ShellExecuteA" ( _
	ByVal hwnd As Long, _
	ByVal lpOperation As String, _
	ByVal lpFile As String, _
	ByVal lpParameters As String, _
	ByVal lpDirectory As String, _
	ByVal nShowCmd As Long) _
	As Long

Then to use ShellExecute use code like so:

Sub ShellExec()
	Dim strFile As String
	Dim strAction as String
	Dim lngErr As Long

	' Edit this:
	strFile = "c:\somefile.txt"  ' the file you want to open/etc.
	strAction = "OPEN"  ' action might be OPEN, NEW or other, depending on what you need to do

	lngErr = ShellExecute(0, strAction, strFile, "", "", 0)

	' optionally, add code to test lngErr

End Sub