I want to transfer the data from excelsheet to data table,one by one entry can any one help me to do so or send code for that in c#

i have one excel file & wants to insert that file with records in to data table??? can any one help me to do so????

if i have a string like "100-A",i want to autoincrement it like 100-A,100-B,100-C......100-Z,100-AA,100-AB,100-AC......100-AZ,100-AAA,100-AAB ...... CAN ANY ONE HELP ME TO DO CODE FOR IT?? I ALREADY DONE CODE LIKE public string autogenrate1(string strauto) { object max; string m; int count = 0; max = ExecuteScalar(strauto); if (max == System.DBNull.Value) { m = "100-A"; return m; } else { string n = Convert.ToString(max); string character = ""; for(int t=0;t<n.length;t++)> { if (n[t] >= 'A' && n[t] <= 'Z') count++; } if (count == 1) { for (int i = 0; i < n.Length; i++) { character = n.Substring(i, 1); } switch (character) { case "A": character = "B"; break; case "B": character = "C"; break; case "C": character = "D"; break; case "D": character = "E"; break; case "E": character = "F"; break; case "F": character = "G"; break; case "G": character = "H"; break; case "H": character = "I"; break; case "I": character = "J"; break; case "J": character = "K"; break; case "K": character = "L"; break; case "L": character = "M"; break; case "M": character = "N"; break; case "N": character = "O"; break; case "O": character = "P"; break; case "P": character = "Q"; break; case "Q": character = "R"; break; case "R": character = "S"; break; case "S": character = "T"; break; case "T": character = "U"; break; case "U": character = "V"; break; case "V": character = "W"; break; case "W": character = "X"; break; case "X": character = "Y"; break;