How to call an existing member within the @SLN function for the "lifeMbrConst" parameter

Hello everyone,

I am trying to leverage the @SLN function within a member formula, and want to use an existing account member as the selection for the lifeMbrConst parameter. My equation is here:

IF(@ISMBR("Custom - EDP equipment"))

@SLN("Input",0,"Asset Life",@LIST(@XRANGE(&FcstYr1->"Jan",&FcstYr1->"Dec"),@XRANGE(&FcstYr2->"Jan",&FcstYr2->"Dec"),@XRANGE(&FcstYr3->"Jan",&FcstYr3->"Dec"),@XRANGE(&FcstYr4->"Jan",&FcstYr4->"Dec")));

But doing that won't generate any data. However when I hardcode the lifeMbrConst parameter:

IF(@ISMBR("Custom - EDP equipment"))
@SLN("Input",0,24,@LIST(@XRANGE(&FcstYr1->"Jan",&FcstYr1->"Dec"),@XRANGE(&FcstYr2->"Jan",&FcstYr2->"Dec"),@XRANGE(&FcstYr3->"Jan",&FcstYr3->"Dec"),@XRANGE(&FcstYr4->"Jan",&FcstYr4->"Dec")));