I think your question is if I have a tree methods to price American option , can I use or modify it to European option.
To that question, the answer is yes and simple. American options need one more step than European one to calculate value at the nodes of exercise:
Max(intrinsic value, discount value from next (time) level nodes )
If you remove these Max (…, …) from American tree except maturity nodes which only have intrinsic value, then you get the European tree. Ie just use discount value from next level notes as the value at that node for European options.
Or if not, It may be interesting to know what your acadmeic research is about. I am not sure if any quants would go crasy to do N dimensional M-nomial trees.