Formulas should be presented after conversion "as is." If a formula is not recognized by Excel as a formula, one can do the following:
1) Change the format of the cell to General.
2) Open the cell for editing and remove the = sign at the beginning (and also the ' sign, if presented).
3) Type = (i.e. put the = sign back)
3) Press Enter to finish editing.
This article refers to Able2Extract and Able2Extract Professional.