Custon Function to Interpolate Table Error

Originally Posted by shg

Cross-post: http://www.ozgrid.com/forum/showthread.php?t=79252

I read the rules as OzGrid but being my first post, had trouble applying them all. I posted here and at OzGrid because when I posted at forums for motorcycle repair, I found that tapping into multiple resources produced many unique, and insightful responses. Also, being my first post, I wanted to see what forums had the fastest and best responses so all I'll need to do is post to one forum.

I never knew VBA forums were so stringent, but VBA Noob provided some insight.

I just tried the function on the same worksheet that has the range data (ITC) and it works fine. So, UDFs have a problem with how I brought in data from another worksheet to create a range for the solution. Any ideas how I can change this to make it work? These lines are causing the error:

    Set rnge = Worksheets("ITC").Range("A3", [A3].End(xlDown).End(xlToRight))
    Set mtrnge = Worksheets("ITC").Range("A3", [A3].End(xlDown))