I've just tested out your most recent suggestion, and it worked!
There is only one issue with the document - since the user is more likely to enter the "LastExamination" text after they have entered the "Frequency" text how would I go about modifying the code to calculate the date after the "LastExamination" field is entered, rather than after the "Frequency" field. An even better solution would be to have it calculate/modify the "NextExamination" date after the "Freqency" or the "LastExamination" field is entered. Basically, that would mean that the "NextExamination" field would be populated correctly regardless of which order the user fills in the document; because at the moment, if the "Frequency" field is filled in before the "LastExamination" field (which is now at the bottom) the document displays a VBA error [Type Mismatch] - I can forsee this being an issue since trying to explain to the users that they need to fill in the bottom before the top will blow their minds!

Any help that you could provide would be greatly appreciated; I did try to work it out myself, but the code is far too complex for me - my status on this site describes me perfectly - "Novice"!

Kind Regards,
Callum