Changing max health

Is there any way to change the maximum health of a unit through triggers? Also, if that's not possible is there a way to add new attributes and change what they do? Or even if it is possible I'd still like to know about the attributes. From what I've seen so far adding a new attribute would require making a mod, but I just want to know about a single custom map. Thanks.

Edit: Or maybe there's a way to change the Item Health Bonus ability so that it targets another unit and lasts for a certain period of time. I could just spawn a dummy unit and set duration to 0 on the spell(so it lasts forever). And also, in case you need to know, the reason I need this is to increase a unit's max health every level, but without increasing strength. As you can see, another attribute would work for this too, and actually probably work better, because I could name it Stamina or something and just have it add a certain amount of health like strength does.

Edit 2: Tried the method described in my first edit..didn't have any luck, even after changing a bunch of things around.

Check Vex InvX Bounus Mod. It has exactly what you want.

Note: Your sig is too wide. Check the Off-Topic for specifications.

Yea realized that the day after I put the sig in, but I haven't been able to get into the CP since then for some reason so I can't really change it.

Edit: I found a way to do it without slogging through all that code Vex has(maybe it's easier than I think it is but it seemed like there was too much stuff you had to do to get it to work, and even then I wouldn't understand half of it.) Just make an upgrade based off the Animal War Training upgrade and it works fine.

Try using the version i made.

http://www.seiken.co.uk/momm/maps/Bonuser%20v1.2.w3x

Works just as well as Lord Vexorian's.

Wierd, when I tried using the Upgrade idea, any units with that upgrade in their Used Upgrades field died every time it learned an ability..which makes no sense at all =\. Anyways, thanks for that dl, I'll check it out.

EDIT: This is exactly what I was looking for =D. Even allows you to edit armor and damage! Thanks a ton.