NEED advice; replacing odd window screens

Moved into this apartment November 2009; learned that bedroom paired windows open vertically, using a crank.

No storm windows, & cheap fabric screen-window inserts, suppposedly "secured" with a retractable pin on the vertical sides of each pane.

Replacement (glass) storm windows (by local glass/window company), omitted the retractable pins, that SHOULD have been evident with the screen window brought in for proper sizing & match.

With these windows, the storm window panels must be removed - then the screens inserted, & "locked" into place, by the retractable pins.

These screen panels fit - kinda/sorta/mostly... they DO have the retractable pins, to match up with the holes in the window frame...
-- BUT: my older (chubby) cat has claws, loves windows, and on her very first "bounce" at the fabric screen window, her claws snagged the fabric, and the panel was knocked out of its moorings.

I NEED NEED NEED, to make (by myself) a fitted metal-mesh screen to fit an odd-shaped window - AND learn how to affix this metal-mesh screen without drilling more screws into the window-sashes & woodwork. (the owners/managers don't care about the woodwork - but I DO - so there's got to be some types of clamps, that can be loosened for weather changes.... I just don't KNOW about them, yet.

I am hoping somebody can help me, help myself - with advice that will fit into my extremely limited budget.

It's been far too long since my last vision (and bifocal) updates... I have to save up, and haven't gotten there yet. but my 2 cats deserve to have fresh air, and nice breezy (but safe) window seats.

 

Aluminum screens are easy enough to make if you can find the parts. It's been a while since I bought any but I used to get the metal at a local hardware store that did glass repair. Check Home Depot or a glass dealer in your area. As far as how they are made, you cut the aluminum to the correct length and width then insert 90 degree corners into the top of the channels. The screen is held into place with a rubber spline that gets rolled into the groves on the frame. The rolling tool looks like a pizza cutter but is blunt. You can get the spline and tool at Home Depot. Don't make the screen too tight or it will pull the frame together in the center. Also allow enough screen so that you can pull on it and cut it off with a razor when done. Holding it in will be a problem since you won't be able to but the pins or tabs that the manufacture uses.