Microsoft Excel - Macro to extract text between two symbols?

Hello.  I'm fairly new to Excel VBA and I've been striking out with making an excel function that pulls the text from between two symbols.  It would be something like xxx|yyy%zzz.

I've had success pulling from one side or the other but when it comes to grabbing the middle part it's a no-go.
I can get xxx
I can get zzz
I can't get yyy

I used this format for the first and second argument
Pipe$ = Left$(String$, PipePlace& - 1)

with one being left and the other being right and PipePlace being a InStr defined dim, but is there a way to grab the middle with this same kind of format?  I'm running out of ideas.

Mid("xxx|yyy%zzz",InStr("xxx|yyy%zzz","|")+1,InStr("xxx|yyy%zzz","%")-InStr("xxx|yyy%zzz","|")-1)

I'm actually looking for VBA.  I have a three case function that I'm trying to create that gives either side or the middle of the string between the symbols depending on whether the user chooses 1, 2 or 3.  The function basically is like this

'Case 1
'Pipe$=Left$(text_string, len(text_string)-symbol_side-1)

'Case 2
'Pipe$=Right$(text_string, len(text_string)-symbol_side)

'Case 3
'Pipe$=Right$(text_string, len(text_string)-symbol)

depending on what the user puts in the function 1, 2 or 3 they get a different piece of what lies on either side of the symbol:  

This is what|I want to get the%user to have.

1 would get-This is what
2 would get-I want to get the
3 would get-user to have

and I need it to happen in VBA.  I have had luck with either side but still keep getting a number with case 2 instead of the middle portion.

Thanks so much, Jonathan!  I had to step through it and figure out what went where but it worked!  Thank you so much!