Vertical bar errors

[WuiChi]

I have had issues with using vertical bars when typing code in to the
expression builder( the expression builder uses them as default). When I
replace them with commas to try and get it to work. Different error but
same implied message - I am not using my commas correctly. Here is code
someone else wrote as the control source I am trying to add a new text box
with another value. Vertical bar error when I cut and paste the code but
works in the text box it is in. Am I missing a reference to get the vertical
bars to work?/ Help

code
=IIf(([Request Decision]="Approved")|([CountOfRequest Decision])|"")

 

[Jerry Whittle]

=IIf([Request Decision]="Approved", [CountOfRequest Decision], Null)