Crystal Reports Multi-replace / replace between

Message

   I have a field in my DB that contains concatenated data (PO# & temperature), like this:

5005219/-10, 5005220/0, 5005303/34

The user now wants to see it like this (one entry per line, omit the temperatures)

5005219

5005220

5005303

I can get as far as replacing the commas with line breaks and stripping out spaces using this formula:

Replace(Replace({<MyFieldName>},",",chr(13)+chr(10))," ","").

That gets me halfway there, with this result:

5005219/-10

5005220/0

5005303/34

Not bad, but how would I now replace the slash and unknown number of characters after each slash? Some temperatures are negative, some are zero, and some are positive, so the number of characters after each slash will be somewhere from 1 to 3, and all but the last instance of those would be followed by chr(13) once the above formula is applied.

So, ideally, I suppose I would take the entire formula above and

1) delete from slash to the character before chr(13). If there is a way to do this (i.e. delete multiple instances from a known character to the character before another known character), it would get rid of all except the last slash & temperature. Then that could be removed by 2) replacing the slash and all following characters (i.e. the final temperature).