Move tab from Workbook1 to Workbook2 using Macro VBA

[nachousa]

I have workbook1 open and I want to move one of its tabs to workbook2.
Workbook1 and workbook2 may vary. I used the "Application.GetOpenFilename" to open workbook1 and now I have
to use it to open workbook2.
This is what I have so far.

Sub Transfer_Button()
''open workbook2
aux = Application.GetOpenFilename("Nam22, *.*")
If aux <> False Then Workbooks.Open aux

'So I want to take the DATA tab  from workbook1(which may also vary), 
'But since I just 'open WB2, it will try to perform the action in WB2.

Sheets("DATA").Select

''''WB1("DATA Tab") ====> WB2

Sheets("DATA").Move Before:=Workbooks("Workbook2??").Sheets(1)

End Sub

This is kinda confusing because I dont want to use any specific names since both WB1 and WB2 may vary,
Do you follow?

Any Ideas??