Passing a variable to Map Role( Shape Name Use(...))

[#1]

I'm playing around with applying come custom map shapes, I've got them to work in the static case:

dt_Wafer:Die << Set Property("Map Role", Map Role(Shape Name Use("N:/JMPMaps/X1234-Name.jmp","Name")));

But trying dynamically is messing up the file name (dt_Info:Product Name[1] is "X1234")

maps = "N:/JMPMaps/";
ProductName = dt_Info:Product Name[1];

dt_Wafer:Die << Set Property("Map Role", Map Role(Shape Name Use( maps || ProductName || "-Name.jmp", "Name" )));

JMP here thinks the file is  N:/JMPMaps/Concat 
Is there a combination of Eval/Eval Expr/Parse/Eval Insert I need to use?

[#2 · Accepted solution]

Most likely Eval + Eval Expr could work

Eval(EvalExpr(dt_Wafer:Die << Set Property("Map Role", Map Role(Shape Name Use(Expr(maps || ProductName || "-Name.jmp"), "Name" )))));