Need help editing a LISP command I am using for better usability

[eb14]

Hey guys, this is my first post on this forum so thanks in advance for any help. Currently I am using Lee Macs "Field to attribute" lisp command to get the length of a line (a steel beam in this case) and insert the field into a block to get an item count. Currently I've modified the LISP command to format the length from feet-inches into a single number to represent a 1' spacing of our product. What I want to do is either take that field value (the length of the beam) and and 1'-0" to it, or take the formatted value and add 1 to it. The reason is when we draw our beams we like to shorten the lines by 6" on each side so we know what beams are separate members and which are continuous. This causes the field value to be 1'-0" less than it should be. Any help on this would be appreciated.

[BIGAL]

"formatted value and add 1 to it" the field command string supports "+" 

 

something like  "%<\\AcExpr  %<\\AcObjProp Object(%<\\\_ObjId 1677668864>%).Length>% + I.0 >%" will have to work out correct string. Trying google. I have add attributes so not sure why "+" is not working.