On selecting this option from the StripeX menu the following dialog appears :
We need to specify the string in the line we wish to extract (in the above this is 'HANDVEL') and whether it must occur at the start of the input line or anywhere in the input line (for the above we have specified that it can occur anywhere in the line). We also need to know how many lines to extract including the line that has the key string. In the above we are just extracting the line that includes the key string.
There are a number of output options, we can load the processed input file to either the currently selected cell or to the start of the current sheet. We have the option to write all occurences of the key string to the same sheet or to individual sheets and finally whether the occurences are written by increasing row or column.