In beas you can define up to 4 UDF's in configuration wizzard

 

in Beas form the system make the udf visible/unvisible and se all format settings

 

with this command you can set the UDF's for this datawindow

dw_1.udf(udf-setting-name as string, [ColName as String],[directRedraw as Boolean])

Example in load event:

dw_1.udf("stl_udf"); // use Bill of Material UDF definition and use column udf1-udf4 in dw_1
dw_1.udf("stl_udf","beas_stl_udf"); // same, but use beas_stl_udf1-4 in dw_1

Outside this events this function not working, because you define only the settings

 

dw_1.udf("stl_udf","",true); // with this command you can define and redraw directly