Well I agree that should work. I see in the help:
Select in Field
Selects the values and fields that are specified. In the Search String you can specify a search mask, e.g. (A|B) will select both A and B.
I've noticed that that it will select correctly if the search string is either: '88311 Decalcification procedure' or '88342 Immunocytochemistry, each antibody'.
But if my search string is: (88311 Decalcification procedure|88342 Immunocytochemistry, each antibody); that nothing is selected at all.
I don't know if it matters that the field I use is a concatenation of other fields -
LOAD Code As CptPathCode,
Description As CPTDesc,
Code & ' ' & Description As Charge;
Yes, blanks are not understood in this action, you can use a wildcard instead
I don't see any problem with the concatenation, but you can use (if that field is going to be used in the above) something like
LOAD Code As CptPathCode,Description As CPTDesc,Code & ' ' & Description As Charge,Replace(Code & ' ' & Description, ' ', '*') As SearchInCharge;
And use the latter in the "Select in Field" action.
Hope that helps.