Hello,
I'm always eager to take up this kind of non-traditional applications. It has to do with my long interest in the AI field. What you're requiring has a remote resemblance to what's called "Expert Systems", in the sense that it'd be driven by a set of rules to produce a result.
While your application isn't supossed to throw some expert advise, but just automate repetitive calcs like a "macro", yet it's based on certain pre-coded operations -algorithms- built into rule-tables.
My only uncertainty is C language. I'm not profficient at it, just can read and interpret C programs but lack the in-depth knowledge of a senior developer. I could attempt this in Visual Basic though, with which I've done some nice things related to electro-mechanical control.
If you don't get any more attractive candidates, I can offer you to start off with an initial milestone you will set at some tangible result achievement. It will serve as the basis for the remaining development -- sort of Proof of Concept.
If this first goal is achieved, only then you'll release first milestone payment (which I set at $1000) and then we go for the rest of the project. This way you're only set to accept the initial milestone, commiting only this initial amount, but not yet make it effective (release the payment) until result is achieved. If things don't go as desired, we settle the project as in-complete and you recover your initial amount.
I look forward to your contact, thanks for your consideration.
Grunty.