Hi Luc - thanks for the link I've managed to figure out the MathCAD help article and got a rough version of what i want out of it. So thanks for pointing me in this direction!
One issue - my VBA script doesn't seem to refresh very well upon re-opening the Excel. I need to double click on the MathCAD OLE object so that the macro runs correctly...no doubt missing something basic.
Another thing that was stumping me was the need for real AND imaginary numbers for each input variable...new to all this coding malarky / exact science.
I've copied my VBA macro below in case others come up against this (now relatively easy) problem.
Sub UpdateWorksheet()
Dim MathcadObject As Object
Dim outRe1, outIm1, outRe2, outIm2 As Variant
Dim inRe1, inIm1, inRe2, inIm2 As Variant
'Set a reference to the Mathcad object on the sheet
Set MathcadObject = ActiveSheet.OLEObjects(1).Object
'Read in values to be passed from Excel to Mathcad. Only Real Values Required Here
inRe1 = ActiveSheet.Range("I4:I1000").Value
inRe2 = ActiveSheet.Range("k4:k1000").Value
'end the values over to Mathcad, assign them to variable in0,
'recalculate, and read the results from out0 back into Excel
Call MathcadObject.SetComplex("in0", inRe1, inIm1)
Call MathcadObject.SetComplex("in1", inRe2, inIm2)
Call MathcadObject.Recalculate
Call MathcadObject.GetComplex("out0", outRe1, outIm1)
Call MathcadObject.GetComplex("out1", outRe2, outIm2)
' Place the result values into the chosen Excel cells
ActiveSheet.Range("P4:P1000").Value = outRe1
ActiveSheet.Range("R4:R1000").Value = outRe2
End Sub
