FME 2018: Allow to set style to individual cells with ExcelStyler

Related products: FME Form

From this Q&A: Style Excel cell values

It would be great if the @CurrentAttribute() function could be applicable in a conditional value setting in order to set style individual cells conditionally. For example, allow this setting to set background color to A, B, C, D, and E columns separately according to each value (currently this setting is invalid).

Expected Result:

My use case is the opposite condition, where I have a specific string pattern in my cell, i.e a pair of brackets with +/- integers inside. Operation options similar to the TestFilter would be nice to have.