Hi ya, you need to include both path to visio and file. example:-
Private Sub Command41_Click()
On Error GoTo Err_Command41_Click
Dim stAppName As String
stAppName = "C:Program FilesVisiovisio32.exe H:userdataDoubleDebit.vsd"
Call Shell(stAppName, 1)
Exit_Command41_Click:
Exit Sub
Err_Command41_Click:
MsgBox Err.Description
Resume Exit_Command41_Click
End Sub