I think you should read the posting guidelines in the sticky note at the beginning of this forum as there is a lot of informaiton you need to give us before we can answer your question.
In particular, you need to tell us a bit more about what is variable and what stays the same in the text you will be examining. Are you looking to see if the string of character "67" occurs anywhere in the string? At a specific place? If the string were "567" would the "67" part still match? etc......
Susan