This is where the search begins. If it is 5, the search starts from the sixth character of the string. Ignore the previous one and replace it somewhere in the search content, and you will replace the whole string, but put the part that does not need to be modified in the replacement string. For example, if you search ABC 1235 and want to replace 1235 with 9875, then you can set the replacement string to ABC9876. If the position to be replaced is not fixed, then you have to deal with it again, leaving what is needed and replacing what is to be replaced.