After looking myself and inquiring on Efnet's #mIRC, I was unable to find a command line form to perform the function found in the default use of ALT+F1. If I failed to find it, my apologies.
The ALT+F1 default use is that of "show/hide subwindows" for a given server (also used as ALT+LClick on a server status window). Most obviously, and command line form of this key combo would allow the changing/customization of the function keys. It would also be very convenient to be able to script such a command to minimize what CIDs or network instances are functioning only as "script clients." I, personally, use a network instance identifier to determine whether or not my scripts fire, and to be able to reduce the "script client" windows would greatly remove excess clutter on my 4-line mIRC switchbar.
In addition to this, if channels could be hidden in the same fashion as this command using the little red indicator on the server status icon, or if that icon could be enabled manually, it would greatly facilitate in additional reducation of switchbar clutter. The existing /window hide/show method is sufficient, but does not make it apparent when a window is hidden in a given server. Though, there are some instances when this behavior is desireable, so the current situation with /window is preferred. Instead, perhaps add such a function to the proposed command form as above.
A suggest syntax might be similar to /close:
/show [email]-icfgms@[N1][/email] [N2] [N3]
/hide [email]-icfgms@[N1][/email] [N2] [N3]
...where the switches correspond to the /close switches, [N1] corresponds to the Nth matching window, [N2] corresponds to a connection ID, and [N3] and tokens thereafter correspond to window names or potential matchtext (wildcard/regex). Not using any parameters would match all windows for [N1], the active CID for [N2], and all windows for [N3]. This syntax is preferred as in the event [N2] is not a number, it can be assumed to be matchtext, eliminating the need of another switch. Although, to prevent confusion, a switch wouldn't be discouraged either. These commands would, of course, imply the icon change in the server status button.
If this is clearly too much work, ease-of-use features could be removed to a bare: /show Name /hide Name where the CID is assumed to be active. If this is also too much work, then perhaps simply an additional switch could be added to /window alongside -h and -w (hide/show): -I : icon change for given server status window. This, of course, implies that the icon would have meaning in that using the ALT+F1 or ALT+LClick method would again display the hidden windows.
Sorry if I was a bit too excessively detailed. I like to be specific.
Thank you for reading this,
~Jinx