A little question related to upper and lower bits in SOC

I want to make my Blake character constantly emit little circles while thokking through the air. Problem is, I don't know exactly HOW to write upper and lower bits, the wiki page was a bit vague...
I want to use A_SpawnObjectRelative.
A little syntax would be nice.

var1 = (upperbitvar<<16)+lowerbitvar

Thank you very much.