Crystal Reports 2 nontrivial problems (for a Newbie)

Message

   Hello!

I'm quite new to CR xi, so I ran into two problems:

1.)
I've got a table Tbl1 containing a field 'weight' and have to display it's value in two columns P and G in my report depending on a value of another table Tbl2 that is referenced by a foreign key field.

Tbl1:                                          TBl2:
...                                               ...
weight (int)                                loadstate_ID (int)
fk_loadstate_ID (int)                  loadstate_val (char(2))

If loadstate_val is 'P' the 'weight' should be placed in column P, if loadstate_val is 'G' in column G.
What could be the best way to do this? I tried to solve this by a SQL Command but found no way.

2.) 
How can I pass the selected value of a parameter field to a SQL Command?
I tried 'Parameter Create' in CR's SQL Editor but I all i got is a second prompt?!

thanks, Frank