.H2 .CLRSCR .HIGHLIGHT
.H2 ( value -- )  
<PFE-SMART>
print hexadecimal, but with per-byte 0-padding
   0x0     -> 00
   0xf     -> 0f
   0x12    -> 12
   0x123   -> 0123
   0x1234  -> 1234
   0x12345 -> 012345

reference: p4_dot_h2 in ../src/yours.c:0523, export CO .H2