The problem is that you are not telling us enough information, you are just supplying bits that are hard to put together.
Where is the data coming from?
How does it arrive? ASCI, or raw hex or what?
It's length is either 46 or 50 chars and chop out what i need.
So is there a way of telling which it is?
Does the data you want always start a fixed number of characters in from 04