AutoCAD Inventor :: Driving Parts With Parameters From Assembly?

How can I drive parts from an assembly level without using Excel spreadsheets. I know it is possible using iLogic to do it, but I can't figure out how to do it "automatically".

For example, we would like to drive a conveyor roller without the use of a spreadsheet. I figured out I could simply insert user-driven parameters in the top-level assembly and drive the parts with the parameters in the assembly, but it is telling me it would cause a cyclic redundancy, so I cannot do it this way, then I thought about iLogic.

It is currently working OK, but I have to enter in the iLogic rule to manually change the filenames in the rule for it to work.

Why? Mainly because we use a prefix to our parts and we sometimes use Autodesk Vault, sometimes not (depending on the project).

Here is my example;

I have a part named "Tube.ipt", "Bearing.ipt", "Spring.ipt" and "Tige Hexagonale.ipt" along with this code in the assembly level (Rouleau.iam):

Parameter("Spring:1", "GAGE") = WIRE_SPRING
Parameter("Spring:1", "DE") = OD_SPRING
Parameter("Spring:1", "LONGUEUR") = LENGHT_SPRING
Parameter("Tube:1", "LONGUEUR_TUBE") = RL-Parameter("Bearing:1", "EPAULEMENT")-Parameter("Bearing:1", "EPAULEMENT")
Parameter("Tige hexagonale:1", "LONGUEUR_HEXA") = RL+B+B
Parameter("Tige hexagonale:1", "BOSSE_SPRING") = B+0.010 in+Parameter("Bearing:1", "EPAULEMENT_SPRING")+LENGHT_SPRING+WIRE_SPRING
Parameter("Tige hexagonale:1", "BOSSE_BEARING") = B+0.010 in+Parameter("Bearing:1", "EPAULEMENT_SPRING")

As you may see, I would have to change "Tige hexagonale:1" every time we use this assembly on different project for it to update properly. I would like to automate it a little bit more.

How to make it work in iLogic:Search for something that has "Tube" in it's filename in this assembly, then store it into a variable called "Tube" Repeat this step for "Spring" and "Tige" Then replace "tige hexagonale:1" by the variable or something like this...