I want to reference the values of row (all columns) 1 in sheet 1, in a
columns (horizontally) in sheet 2. The formula should look something like
this:

=SHEET1!A$1

This is a problem, cause the "A" in the formula stays constant, and needs to
change to B,C,D,E,F,etc.

How do I get it to change when filling the formula by dragging?