Clear past data from a measure within specific date range

There is a requirement to clear a measure data of a specific date range. I'm using the below mace command, but getting below error.

Want to clear data within date 01-Dec-17 and 31-Dec-17

mace -d /rpas/RDF/domains/RDF -run -expression "TstNvPriceR = if(!TstV1SkugB && position([CLND].[day])>="20171201" && position([CLND].[day])<="20171231",0,ignore)"

Measure 'TstSkugB' base intx is at skug level.

Measure  'TstPriceR' base intx is at str_sku_day_ level

Any urgent help will be highly appreciated.

Error:

<E 2018Jan14 08:09:01.812> Illegal types for sub-trees: position([clnd].[day]) and 20171201 long

<E 2018Jan14 08:09:01.813> Expression::restoreExpression() caught exception

<E 2018Jan14 08:09:01.813>   Exception:  'IllegalParse: Failed to validate parse tree.