Open 2nd Workbook From Userform Then Close 2nd Userform?

What I would like to do is to be able to open a second workbook from a user form, preform some work on it then save and come back to the same place in the original user form.

So in steps:

1 : user clicks command button to open user form
2: user then clicks on command button on userform that opens 2nd workbook via a yes / no message box, but closes userform on 1st workbook (would be ideal if this could stay open, but hidden)
3: user then does work on 2nd workbook,
4: userform on 2nd workbook saves then activates the 1st workbook and reopens the userform

This is where no matter what I try I cant get the command button on the 1st userform to be clicked automatically so the yes / no message box appears.

This is part of the code in the 2nd sheet commandbutton that saves / closes / opens

Code:
Unload Me
ActiveWorkbook.save
Windows("ABC.xlsm").Activate
Sheets("Request Sheet").Activate
Call Sheets("Request Sheet").ForceClickOnBouttonXYZ
Call UserForm1.CommandButton6_Click 'this is where I cant get it to work!!
Windows("xyz.xlsm").Close
ABC is the 1st workbook
xyz is the 2nd workbook

This is the code on the 1st workbook I use to call on the 2nd workbook

Code:
Public Sub ForceClickOnBouttonXYZ() Call CommandButton1_Click End Sub