Build a formula from a string

[NickAtNight]

How do I build a formula from a string?

Lets say I have 10 user defined functions... (sam, fred, mary,...)

and I want to build the formula in the spreadsheet.

I can use a data validated cell to limit the function to the list of UDF's.

Then I want to create the formula as a string.
'=sam(v1,v2,v3)' or '=fred(v1,v2,v3)'


Then apply the string as a function.

 

[NickAtNight]

{it would be easier to do this in VBA or from a Userform. For this variant, I am trying to do this from the spreadsheet without extra code)

 

[mikerickson]

I'm thinking that you have a validation drop down in B1 with the list of UDF's.
And you have your three variables in A1,A2,A3.

You want a cell to return the value of the function selected in B1, with the variables in A1,A2,A3.

First off, you cannot use worksheet formulas to change other formulas. Excel worksheet functions can't change the evironment of the worksheet (like change cell colors or change cell values). Worksheet formulas return values. So what you could do is have your UDF's

Sam, Fred, Mary, ...

Then have a dropdown with the strings "Sam", "Fred", "Mary", ...

Then create a name
Name: myResult
RefersTo: If(B1="Sam", Sam(A1,A2,A3), If(B1="Fred", Fred(A1,A2,A3), If(B1="Mary", Mary(A1,A2,A3), ... )))

Then put =myResult in a cell.

 

[NickAtNight]

Drat. 'you cannot use worksheet formulas to change other formulas'. I guess that answers this question.

Your proposed solution would work.