UDF Required to get the String value before "-"

Hello Experts,
I have been stuggling from past 5 days to get this done via UDF, have found a number of the UDFs across the web although none of them worked to fulfill my requirement completely here.

This was the closest one I found :

UDF Required to get the string before pipe

The solution provided in the above case is getting me only the first vlaue, However, in my case I need all the values eg. 1;3;4;7

Input value : 1-Dummy1; 3-Dummy2Dummy; 4-DummyISO4000; 7-MAN IN THE BOX

Expected Output value: 1;3;4;7

OR COULD BE THIS

Input value: 1-DUMMY2; 2-DUMMY3; 5-DUMMY TIP SYMBOL

Expected Output value: 1;2;5

OR COULD BE THIS

Input value: NA

Expected Output value: NA

quick help would be appreciated.