I'm sure you will get other answers more directly related to using offset;
I'd do something like the following (just because it is what I know):

NumColumn = Range("J2")
CharColumn =(Asc(UCase(NumColumn )) - 64)
Columns(CharColumn & ":AC").Select

This is aircode, so it may need some tweaking... and it will only work up to
a start column of Z; after that the CharColumn will give you ascii characters
above Z (it won't automatically wrap back around to column 'AA').

HTH,
Keith