program for two measurements that are dependent on eachother

[StephanArch]

I often need to make AutoCAD drawings of custom fabricated bar grilles for HVAC applications. Given a frame, say 24x4", I need to figure out how many vertical crossbars should go into that 24" length and how far apart they should be from each other and from the edge of the frame.

The parameters I like to stay in are these: the crossbars may be anywhere from 0.75" to 2" away from the ends and between 4" and 9" away from each other. The thing is that for the second range I gave, I can only allow 0.25" increments. So to reduce material usage naturally we would like to see if a 9" spacing is possible given the end parameters before trying 8.75, 8.5, etc. all the way to a minimum of 4". The first combination of crossbar quantity and spacing that meets these criteria is usually the one I go with for my drawing and the paperwork I send to the cutting department.

I'm pretty sure this can't be done with regular excel formulas. I have no experience with VBA but I'd like to start learning by using it to solve this issue. Would anyone on this forum be able to help?

[Arkadi]

I have made a basic spreadsheet that I think approximates what you need... It does assume that the space from the edge of the frame is the same on both ends, and that the thickness of the crossbar needs to be taken into account.

Of course you can set crossbar thickness to 0 if I've assumed wrong on that.