Scan From String White Space

Question

i all,
I'm trying to use Scan From String in order to parse some data coming in from UDP. 
Input String: ASCII [00 01 02 03 ... FF]
What I want: s[00 .. 30]  d[12], d[34], d[56] leftover s[37 38 39 ... FF]
ATTEMPT1
Format String: %49s%2d%2d%2d
What I get: s[00-09] RUNTIME ERROR!
ATTEMPT2
Format String: %49[^]%2d%2d%2d
What I get: Only allows first output. Will error out if I use any additional outputs from Scan From String
ATTEMPT3
Format String: %49[^(0xFF)]%2d%2d%2d Value in () is ASCII character FF.
What I get: s[00 .. 30] d[12], d[34], d[56] leftover s[37 38 39 ... FF]
It appears as though when I use %##[^] it thinks I'm looking for the ENTIRE string so it will not let me add any more Formatting.  If I add a delimiter other than ^ it will run, and it will work presuming that character isn't within the first 49 characters... and I can't guarentee that it won't.
I'm aware I can parse my string using subsets and whatnot... but Scan From String is so elegant.  It would be great if %S allowed for white space... or if $##[^] would simply take the first ## characters and allow me to Format after that.
Is there a simple, elegant way to do this?  I wish my dataset was only 3-4 outputs. It'd be ideal if I could.  Thanks.
Edit:
It might be more helpful if I provide a less abstract example:
I have an ASCII Header (Finite Length String), a Sender IP (Finite Length String), a Timestamp, a Message ID (Finite Length Decimal), A Message in ASCII ( '1' actually means 0x31, not 0x01)  And for some ungodly reason... no delimiters.
So I was HOPING %##s%##s%<%H:%M:%s>t%##d   (With leftover string to be my message)  would work, but if any white space is contained within there... it messes up. 

Answer 1

I cannot provide exact strings because the string is actually ASCII characters, most of which aren't displayable. 
I have a string where I have:
24 ASCII Characters representing 6x U32 Header Data
13 ASCII characters represening the sender IP (string)
12 ASCII Characters representing the name of the message (String)
12 ASCII Characters representing 3x U32 Data
12 ASCII Characters represneting the name of packet (String)
12 ASCII Characters representing 12x U8 Data
256 ASCII Characters represening 256x U8 Data
etc...
It would be ideal to simply Scan from the string and output the data with the appropriate data types already assigned instead of splitting string and type casting each individualy.  But if, for example, my header starts with an ASCII representation of a U32 of 2560(decimal) it would look like this:  [00][00][0A][00].  ASCII 0A is considered white space.  So my header would only contain 2 ASCII characters instead of the desired 24.