Not sure if this is possible or how simple it is (for someone not so clued up
on Excel).

My boss uses a lot of worksheets and has to enter a lot of things numerous
times on different sheets (Company Names, Account Numbers, Rep codes etc etc).

He has asked if it is possible to create some kind of programme or function
that would mean if he created one main sheet with all the details on, that on
other worksheets he could just enter the company name it would bring up the
rest of the details?

(sorry if that doesn't make much sense)