Program to place the bus pins

Hi,

I am trying to write a program to place the buspins for example APT<4:46> in given pitch in given layer.  For this I wrote a program as given below

procedure( buspins()

cv=geGetEditCellView()

point=enterpoint()

pin="APT<4:46>"

pins=parseString(pin "<>")

name=car(pins)

num1=cadr(pins)

num2=parseString(num1 ":")

start_num=car(num2)

start_num=evalstring(start_num)

end_num=cadr(num2)

end_num=evalstring(end_num)

when(start_num!=end_num

label1=buildString(list(name "<") "")

label2=buildString(list(label1 start_num) "")

label1=buildString(list(label2 ">") "")

dbCreateLabel(cv list("M2"  "label") point label "centerCenter"  "R0"   "roman"   0.28)

start_num=start_num+1

return()

))))

when I am trying to excute this progrm I got the error in virtuoso is        "Error* ilGetString: arg must be symbol or string "

I think this is due to start_num variable is a number not a symbol or string. start_num contains a number without double quotes.

If that number is in double quotes (by removing start_num=evalstring(start_num) line)  label created but we can't do addition operation for it i.e., start_num=start_num+1.

So, how to add double quotes to a number. Is there any instruction for it. otherwise please tell me how to do this program.

Thanks,