Display from a listbox selection

i have used this code to display First Name from a .txt file to a Listbox
Private Sub cmdOpen_Click()
lstName.Clear
If txtFile.Text = "" Then
MsgBox "No filename entered", vbInformation, "Error!"
Else
Open txtFile.Text For Input As #1
Do While Not EOF(1)
Input #1, strFirstName, strLastName, strPhone, strDate
lstName.AddItem strFirstName
Loop
Close #1
End If
End Sub
Private Sub lstName_ItemCheck(Item As Integer)
...? ? ? ?...
End Sub

What I would like help to code is a:
1) return a msgbox if the filename entered does not exist when cmdOpen is clicked
2) when a string(FirstName) from the listbox display is selected the other data associated to that selection(LastName, Phone, DOB) is shown in corresponding label boxes

thanx in advance:D

I was trying to get the date to display in a caption and i was told i need to make use of the CDate() function.
I was given this example
strDate="26/07/1975"
dteMyBDay = CDate(strDate)
Can somebody please explain to me how to use this function in my code