Multiple placeholders in a string inside an Iff statement in SSRS

I've got logic that a text field that has several sentences, I need to break up that sentence to include placeholders (with links). it will look like this

Example: «Expr»[UserEmail]«Expr»[AgreementStatementPage]«Expr»

However my expression reads

if the balance due is greater then zero dollars, the iff logic will read you owe us some money, print the users email (clickable placeholder), some more text followed by a link and some more text.

that said, if the balance due is not greater then zero dollars (or else) the statement starts out differently and then still has the email, and some more text and links ...

example:

= iif(Variables!bal_due.Value > 0, 

   "you owe $$ to be sent to userEmail then some more words and here is link AgreementStatementPage and another sentence.",

   "thank you for your payment that was sent to userEmail then some more language with the link to the AgreementStatementPage and another sentence."```

I don't know how to user the placeholders, with the iff statement, i can't  break up the field because the iff statement has to be there in its entirety in an <<expr>> but then how do I make the links clickable.

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Edit: Even if I break it into 2 logic iff statements, iff > 0, and iff <= 0 I still can't have a partial expression that SSRS will allow to work. Basically how do I get the hyperlinks/placeholder elements into my Iff statement.