If the text was typed with the Shift or Caps Lock key engaged originally, the text should come across that way.
If the text was typed into a document where the formatting determined the use of caps, that formatting won’t transfer.
The closest thing you could do would be to select the pasted text once you’ve released it in the titler, check “small caps” in the text attributes, which will change everything into Caps and will make the “lower case” letters smaller to the percentage value specified. If you want all the letters to be full size, specify 100%.
TimK,
Director, Consultant
Kolb Productions,
Adobe Certified Instructor