I can't get a float vale back

[Jim]

I am codeing a Stored Procedure that is working up to a point where I try to set a variable to dynamically retrieve a float value back from a table

The following code is inside a While Loop

example

...
WHILE myCounter is < 19
Select @fPercent = 30
Select @vCurveType = &#39;One&#39;
...
IF Condition1
...
IF condition2
begin
exec @fCurveFactor = &#39;SELECT &#39; + @vCurveType + &#39;FROM tlbCurves WHERE PercentComplete = &#39; + @fPercent
...
end return
ELSE

...

If I hard code the Select statement it returns a valid value (like .024
The way it is my return = 0

any ideas on how I can acomplish my goal?
Can the Column name be set using a variable?

Thanks for any help