If you're talking about rotating text within a Smart Form, we have accomplished this by implementing JetCAPS BarDIMM (see http://www.makebarcode.com/reviews/addin/barsimm2.html). There is a special printer module (DIMM), when inserted into the printer, which allows you to send escape sequences and information through the regular ABAP spooler to your HP printer. The special DIMM allows Smart Forms to rotate text and do other text manipulation. A simple command would look like this to rotate your text 90 degrees:
~&a90p
Other commands allow for exact position (X,Y coordinates) of your text information and variables. The following escape sequence would print the sales document number at a specified location on your Smart Form and use a specific font size and weight:
~*p50x1600Y~(s1p12.0v0s0b16602T&'Order Number: 'VBAK-VBELN&~(
The simpler approach to text rotation would be Adobe printforms. This has built-in rotation capabilities (t-code SFP). You would have to have an Adobe Document Service setup and available on your system before you would be able to use Adobe printforms in your system.