Finding solution by narrowing down

Hi guys,

I am new to this forum and obviously have an Excel VBA question:

I have a macro that finds an optimal solution in K14 while N55 must be 0, apart from some other constraints. The method I currently use consists of starting with entering 0 in K14, check whether N55 is 0, and if not, entering 0.5 in K14, check whether N55 is zero, and if not, entering 1.0 in K14, etc. etc. Excel will find the solution, but it takes a lot of time.

The macro looks like this:

Sub SOLVE()
Dim i As Double

Application.Run "Conversie"
Application.Run "BBV_max"
Application.Run "BBV_max_A12"

For i = 0 To 1000 Step 0.5
    Worksheets("COCKPIT").Range("K14") = i
    Application.Run "Conversie"
    If CLng(Worksheets("COCKPIT").Range("N55")) = 0 Then Exit For
Next i

End Sub

I was wondering whether there would be a faster method of obtaining my desired result. For example, if I know that the value must lie between 0 and 1000, could I use a macro the narrows down to the solution, instead of trial and error starting from 0?
If so, could you help me with such code? Or perhaps, such code is already available?

Please let me know if I do not comply with certain forum rules, as I do intent to.

Thanks for your help!
Pieter