Need some help with Dialog

[InterestedNewbie]

I would like some help with the following Dialog. The TRANSFER button is supposed to copy all text from the edit box, performing an ALT+TAB to switch to the underlying application and then paste the text into that application. After that the dialog has to close. 
I tried to put focus to the edit section, but that didn't work. The only part that does work is the ALT+TAB command:

Function SIMPLE TEXT-BOX 

Code:

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str dd=
;BEGIN DIALOG
;0 "" 0x90C80AC8 0x0 0 0 224 136 "Dialog"
;3 Edit 0x54231044 0x200 16 8 188 96 ""
;4 Button 0x54032000 0x0 108 116 48 14 "TRANSFER"
;2 Button 0x54030000 0x4 168 116 48 14 "Cancel"
;END DIALOG
;DIALOG EDITOR: "" 0x2040700 "*" "" "" ""

str controls = "3"
str e3
if(!ShowDialog(dd &sub.DlgProc &controls)) ret


#sub DlgProc
function# hDlg message wParam lParam

sel message
,case WM_INITDIALOG
,case WM_DESTROY
,case WM_COMMAND goto messages2
ret
;messages2
sel wParam
,case IDOK
,ret
,case IDCANCEL

,case 4 ;;TRANSFER
;Now the edit box needs to get focus.

,key Ca          ;; Ctrl+A (selecting all text in the edit box)
,key Cc          ;; Ctrl+C (copy)
,key AT          ;; Alt+Tab (switch to the active application, so far this is the only thing that works).
,1
,key Cv          ;; Ctrl+V (pasting the text)
,
;After performing the above actions the Dialog has to close.

ret 1