Hi. Using Excel 2007. I want to be able to force information into a cell - in
order to protect or "bullet-proof" the data-capture in order to limit capture
errors. For example: If Column B contains the text: "SAI", then Column C must
default to a 13-digit numeric field. If any alphanumeric or less than 13
digits is captured in Column C, it must not allow this and force an error
message. However, if Column B contains the text: "Passport", then column C
must default to an alphanumeric field of unlimited length (because passport
no's differ in length and some are numeric as well as alphanumeric).

is this possible within Excel's normal functions? Please can you help.

Thanks