What you want to do is possible, but I can't think of any circumstances where I would do it.. The question you are asking points to a very common problem, in that you have created a set of forms which are practically identical, with minor, superficial differences and different data.
The solution is to stick with one form, but change the data displayed in the form. Instead of switching out the form and replacing the form with another form in your subform/subreport control you can directly access the record source of the form. By accessing the forms record source directly and providing it with a different set of data to be displayed. You can also access anything else in the form, the controls, textboxes, comboboxes, hide them, make them visible, whatever you need to do to provide the slight difference you require regarding the particular set of data displayed in the form...
However I've no idea if this is what you have or what you've done, hence as somebody has already asked, what are you trying to do? And can you provide a sample database? Both are important, a good description of the work process you are trying to imitate in MS Access and a sample database, to give us something to hack around and make work in the desired manner...