What I want to do is create another Text Object under that with an action that takes me to SH02 and finds the case on a Straight Chart that only pulls through the case with the oldest case.
This could work if you put the (calculated) sheet and the case in additionally variables and the click-action on the textbox used these variable-values to switch the sheet and select any values and/or set the visibilty for an object on true or false.