The following example creates a new form and creates a new command button on the form. The procedure then sets the control's Caption property and sizes the control to fit the caption.
Sub SizeNewControl()
Dim frm As Form, ctl As Control
' Create new form.
Set frm = CreateForm
' Create new command button.
Set ctl = CreateControl(frm.Name, _
acCommandButton, , , , 500, 500)
' Restore form.
DoCmd.Restore
' Set control's Caption property.
ctl.Caption = "Extremely Long Control Caption"
' Size control to fit caption.
ctl.SizeToFit
End Sub