To Use:
1. Open Enchanting Skill
2. Select Enchantment in skill panel to apply
3. Have Enchanting Vellum in your inventory
4. Press macro
Credit: Ajudication of Terokkar-US

Macro:
/run DoTradeSkill(GetTradeSkillSelectionIndex());
/run for i=0,4,1 do for l=1,GetContainerNumSlots(i),1 do if GetContainerItemID(i,l)==38682 then UseContainerItem(i,l);end;end;end;
/run ReplaceEnchant();
/run ClearCursor();