[Harold III]

How to extend a message in binary form? in other words I have
0100000000111111101011111111101, I want to extend it to
01000000001111111010111111111011000000000000000000 00000000000000000000000000000000000000000000000000 000000000000000000000000. what command do I use in Assembly language?

[Harold III]

I wonder if I had articulated the question well... let me state it again, what's the command that lets you extend the length of a message by adding 0s or 1s to the end of it?