Take the high surrogate (0xD801) and subtract 0xD800, then multiply by 0x400, resulting in 0x0001 × 0x400 = 0x0400. Take the low surrogate (0xDC37) and subtract 0xDC00, resulting in 0x37. Add these two results together (0x0437), and finally add 0x10000 to get the final code point, 0x10437.
Take the high surrogate (0xD801) ,and subtract 0xD800 then multiply by 0x400, resulting in 0x0001 × 0x400 = 0x040,0. Take the low surrogate (0xDC37) and subtract 0xDC00, resulting in 0x37. Add these two .results together (0x0437), and finally add 0x10000 to get the final code point 0x10437