I added some form controls through the developer tab and linked them to macros successfully. They are checkbox type controls and I want to increase the font size in them, when i click edit text though it doesn't highlight or enable me to increase font size. How can I achieve this?
Your easiest option may be to add an ActiveX checkbox, instead of the normal type.
With regular form control checkboxes added to the sheet in this way, the checkbox is actually a shape that you have limited control over (msoFormControl type). You can change the text for the textbox through the .textframe object of the shape, but you cannot format it.
(Although .textframe does support a characters method which would normally edit text in a shape, this doesn't seem to be enabled for this particular type of shape.)
As far as I can tell, this sort of formatting is only enabled on checkboxes in userforms.