grid $variablename {*}$arguments

Note that in the most common case (where the script fragment is actually just a list of words forming a command prefix), it is better to use {*}$script when doing this sort of invocation pattern. It is less general than the eval command, and hence easier to make robust in practice. The following procedure acts in a way that is analogous to the lappend command, except it inserts the argument values at the start of the list in the variable: