Based on your comment to my reply:
If the date is always at the end, you could reverse the string retrive the non-date portion, and then reverse it back:
string x = "ABCDEFG2010124";
string prefix = x.Substring(0,x.Length - 7);
string possibleDate = x.Substring(prefix.Length-1, 7);
x = prefix;
This is basic developemnt stuff. Since only you can identify the patterns, only YOU can come up with an acceptable parsing routine(s). There's no way you can provide all of the variations of the data you're retrieving, so there's really no way we can help beyond analyzing what we know based on what you provide.
Now, it's YOUR turn to be a programmer and come up with the code you need. It's really not that frakking hard.