Thanks Mark. Ironiclly I phoned a colleague to get some help on this and he wasa mid way through the webinar. Perhaps my interuption prevented him from seeing just the right bit
I've been through the example you sent and i'm not sure its exactly what i'm looking for. I am creating a data quality workbench which has an excel workbook to provide 'configuration' . For example it lists all the datasets being run and all their columns. Against each the word yes or no is selected from a dropdown. FME reads the dataset plus the workbook, joins the two and runs its assessment where the user selected yes in the excel sheet. It allows non FME users to configure the run in an application they are familar. I have similar tabs specifiying the length of attributes, whether special characters are allowed, and ahost of other data quality assessments.
One particualr assessment I want to run in FME is to test whether a column matches the result of an equation e.g. DP_TO_INV should match @value(COV_LEVEL)-@value(INV_LEVEL). I have written this in excel and am passing into FME. What I can't figure out is how in enact @value(COV_LEVEL)-@value(INV_LEVEL) in FME - it just sees it as a text value