it depends on how the data is coded. If the data is always two single bytes, you can simply write the bytes to the proper positions of an int.
//write directly to the corresponding positions
unsigned int Test;
unsigned char MSB, LSB;
Test = LSB;
Test |= MSB << 8;
You can also use unions/structs to create the memory layout for the incoming data, but this depends on the situation.If the data is ASCII coded you should use atoi() functions.
And do not forget there are the standard function famiies printf() and scanf() which allows you at both ends to convert your variables to formatted strings and back. have a look here: publications.gbdirect.co.uk/c_book/chapter9/formatted_io.html