I've found this form useful: it's possible to pass an argument to the
evaluate function.
With cell A1 selected define the name eval as below:
eval: =EVALUATE(EVALUATE("if("&MID(GET.CELL(6,!A1),6,250)))
Then you can enter formulas in any cell in the form:
=IF(1,eval,TextToEvaluate)
eg:
=IF(1,eval,"1+2*3") returns 7
or if A2 contains the text 1,2,3,4,5
=IF(1,eval,SUBSTITUTE(A2,",","+") returns 15