Is it possible to edit rules such as crit damage?

Figured I should start a new topic on this. So deleted other post in older thread.

So on the topic of house rules. My players are asking if there is a way to edit/change how crits work. We have played that when you crit you take your damage roll + the weapon+str bonus (or anything that adds to the damage) sum and multiply that by your critical modifier.

The way it is (the way the PHB describes a crit) is roll your damage the number of times your crit modifier.

So is there any way to edit crits in d20pro for house rules, instead of using custom dice (we want to continue to uset he combat system in d20 pro so nothing fancy with fudging dice or anything like that.) I could do it manually obviously, but that's not what we want.

 

Flaming burst is easy. Just go into the attack and add flaming and burst on the same damage line.
So if you have a scimitar of flaming burst. You should have a line that looks like the screenshot below.
So what this does on the 1d10 flaming critical line is add that damage only on a critical. Otherwise it will always come up at 0.