How do I convert COBOL Comp-3 packed to ASCII?

I am receiving a flat file that has a few bytes in COBOL COmp-3 packed format.

I only need to read 6 bytes then unpack to convert to ASCII in 12 bytes.
The first byte will contain a 01 or 02 that will tell me if the number that follows should be considered negative or positive. The number is in the next five bytes and will translate to a number with one decimal position.

Samples:

01 00 00 02 22 22
02 00 00 03 33 33

So, I understand the first byte. But how do I read/convert the number00022?

I looked at Google and saw a few pages explaining ECBDIC but am no closer to a solution.
Any clues from the old timers out here that remember this arcane stuff?