How to split a integer string based on the character present in it

So I will have list of integer strings, I mean, integers converted to strings in my DB like below:

66S12345, 623T4785, 784D3212

So there will be only one occurance of character in the above string.

Now I want to split the string based on the character position and obtain it as S12345, T4785, D3212. But no idea how to get it.

I obtain list of strings as below

using(var context=new ATMAccountEntities()){
     List<string> accountNumbers = new List<string>();
     accountNumbers = (from n in context.Students select n.stdUniqueID).ToList();
     foreach(var acc in accountNumbers) // acc can be 66S12345, 623T4785, 784D3212
     {
          string accNum=  //Any way to split the string and obtain later part after character
     }
};