I use, the following code that I found on the internet, to store the location of a file into a control (field) on a form the control name is display_0005. Replace display_0005 with your control (field) name that you are using on the form.
Code:
Private Sub display_0005_Click()
On Error GoTo Err_display_0005_Click
'Declare a variable as a FileDialog object.
Dim fd As FileDialog
'Create a FileDialog object as a File Picker dialog box.
Set fd = Application.FileDialog(msoFileDialogFilePicker)
'Declare a variable to contain the path
'of each selected item. Even though the path is aString,
'the variable must be a Variant because For Each...Next
'routines only work with Variants and Objects.
Dim vrtSelectedItem As Variant
'Use a With...End With block to reference the FileDialog object.
With fd
'Allow the user to select multiple files.
.AllowMultiSelect = True
'Use the Show method to display the File Picker dialog box and return the user's action.
'If the user presses the button...
If .Show = -1 Then
'Step through each string in the FileDialogSelectedItems collection.
For Each vrtSelectedItem In .SelectedItems
'vrtSelectedItem is aString that contains the path of each selected item.
'You can use any file I/O functions that you want to work with this path.
'This example displays the path in a message box.
Me!display_0005 = vrtSelectedItem
Next
'If the user presses Cancel...
Else
End If
End With
'Set the object variable to Nothing.
Set fd = Nothing
Exit_display_0005_Click:
Exit Sub
Err_display_0005_Click:
MsgBox Err.Description
Resume Exit_display_0005_Click
End Sub