question

There's actually several lines of code in that table cell when you choose a distribution. If you click on the Edit Code button next to the cell when you click on it, or you click Ctrl-A to select everything in the cell before copying the cell, you'll see the full code looks like this:

Object current = param(1);
treenode activity = param(2);
int rowNumber = param(3); //The arrival entry row number
int cycle = param(4); //The current cycle through the arrivals table (first iteration cycle = 1)
treenode processFlow = ownerobject(activity);
/***popup:StatisticalDistribution*/
return
/***tag:distribution*//**/poisson/**//**/(/**/
/***tag:par1*//**/10.0/**/
/***tag:par2*//**/, getstream(activity)/**/
/***tag:par3*//**//**/
/***tag:par4*//**//**/
/***tag:par5*//**//**/
/**/)/**/;

Whereas in the text box below it you just see:

poisson(10.0, getstream(activity))

Most of the stuff in that multiline code snippet is just meta text to make it show up right in the distribution popup. It basically boils down to this:

treenode activity = param(2);
poisson(10.0, getstream(activity))

So the easiest thing to do to get a single line to paste in from Excel is to change activity to param(2) like this:

poisson(10.0, getstream(param(2))