C - Assign value to char using numeric value

I'm writing a simple C program that uses some extended ASCII characters to draw boxes. I'm adding a part where the type of box can be specified, and I want to use char variables in place of "%c", 201, etc. I can't just copy and paste the characters into my editor, because ╗ turns into + when I do that.

How would I assign a numeric value to a char variable? i.e. topRight = 187; except that doesn't seem to work.