editing pcell parameter values, having type mismatch

Hi Cadence -

I created a new pcell and gave it 5 parameter values.  ( param1 thru param5 )

I thought it was going to be easy to feed a new value to the pcell with replaceable text string where I concatenate a string

with a count number:

myPcell = car(selectedSet() ) 

count=1

while(count< 6

    myPcell~>concat("param" count) = newValue

   count = count +1 )

When I do this I get a *error* getsgq: arguement 2 should be a string or symbol

I've also tried myPcell~>strcat("param" count)   and gotten a similar error.

How can I address the parameter name with replaceable variable names ; is this possible ?

thanks.