get the word after search key word

Hi,

Try

List acc = new List();
string keyword1 = "REM ACCT";
string keyword2 = "REM ACCT.";
string keyword3 = "REM ACT:";
string myString = "the amount can be verify in REM ACCT 123456789 number, REM ACCT 44, sample multiple keyword REM ACT: 58945 and using REM ACCT. 58223";
var k = myString.Split(new string[] { keyword1, keyword2, keyword3 }, StringSplitOptions.None);
for (var i = 1; i < k.Count(); i++)
{
    var neededString = k[i].Split(new char[] { ' ' })[1];
    acc.Add(neededString);
}

hope this will help you.