Quote from Zanzer:
Here's a brief explanation about how weapon upgrades and infusions are represented in memory. I will be using decimal notation (not hex) because you will need to use math. Each weapon has a base Item ID value. For example, the Club has the ID 8000000 (decimal). For upgrades, you simply add +1 through +99. So, 8000007 would be a Club +7. Now infusions are a multiple of 100. So for every +100 you'll cycle through each infusion. For example, 8000500 would be a Crystal Club. While 8000507 would be a Crystal Club +7.
Add the following values to the base Item ID for the specific infusion:
+100 Heavy
+200 Sharp
+300 Refined
+400 Simple
+500 Crystal
+600 Fire
+700 Chaos
+800 Lightning
+900 Deep
+1000 Dark
+1100 Poison
+1200 Blood
+1300 Raw
+1400 Blessed
+1500 Hollow
Upgrade and Infusion video tutorial
Demo video by RandomFromdrone
Note: Last Pickup Item Highlighted
is now Helpers->Item Swap
I made a video for this.
ToDo
Thanks Loki for the guide. (Link)