If I understand you correctly, you want to take the string returned by the
userform, plug in the actual values of Fieldx, and calculate the formula.
You could use the REPLACE function and the EVALUATE function, i.e.:

Dim strFormula As String 'Actually, the formula returned from the userform
Dim Field1 As Double 'Example variables you'd want the original values
Dim Field2 As Double '(also from the userform?)
Dim Field3 As Double
Dim Field4 As Double
Dim Value As Double

Field1 = 10
Field2 = 10
Field3 = 10
Field4 = 10

strFormula = "Field1 * Field2 - (Field3 + Field4)" 'String returned from
userform

'Replace function - Replaces one string with another (even if that is a
numeric value)
strFormula = Replace(strFormula, "Field1", Field1)
strFormula = Replace(strFormula, "Field2", Field2)
strFormula = Replace(strFormula, "Field3", Field3)
strFormula = Replace(strFormula, "Field4", Field4)

'Evaluate the resulting string, now with the values plugged in
Value = Evaluate(strFormula)

The only problem I'd see with this is if you had a variable number of
"fields" returned in the formula. You'd need to determine the largest one
(i.e., Field4 above). Then you could put your REPLACE function in a loop
(For i = 1 to MaxNoOfFields) and go from there.


"Tatumsa" wrote:

I have a userform with a list of variables and operators which a user
can press to create a custom formula. The variable text entered by
clicking the button is the same name as that used in the code behind
the scenes. So a user would be able to create a text string looking
like "Field1 * Field2 - (Field3 + Field4)" etc.. Is there a way to
actually calculate a value from the string the userform returns? So for
the above example if all values were 10 you would get the number 80.
All the users are using Excel 2000.