You should be able to adapt my previous macro for use with get label by studying the online help for that command (in R5) which I'm copying in below:
{GET-LABEL [prompt];result;[default];[title];[x];[y]}
Lets the user enter anything that you want 1-2-3 to store in the worksheet as a label.
· If the user types data in the text box and chooses OK, 1-2-3 enters the contents of the text box as a left-aligned label in result.
· If the user types nothing in the text box and chooses OK when the text box is blank, 1-2-3 enters the ' (apostrophe) label-prefix character in result.
· If the user chooses Cancel, 1-2-3 makes result blank and continues the macro.