Evaluate an string.

Evaluate an string. ------------------------------ I would know if it is possible, in 4GL, to evaluate an string. For = example: If I have: let cad=3D'var1+var2+var3' Could I get something like this: num=3Deval cad So, if var1,var2 and var3 are integers, and its values are 1,2 and 3, the = value of num would be 6. Thanks in advance.