Right now, asdoc can tabulate and export string variables. See this example.
sysuse nlsw88, clear
decode industry, gen(ind2)
asdoc tab ind2, replace
industry | Freq. Percent Cum.
------------------------+-----------------------------------
Professional Services | 824 36.92 36.92
Manufacturing | 367 16.44 53.36
Wholesale/Retail Trade | 333 14.92 68.28
Finance/Ins/Real Estate | 192 8.60 76.88
Public Administration | 176 7.89 84.77
Personal Services | 97 4.35 89.11
Transport/Comm/Utility | 90 4.03 93.15
Business/Repair Svc | 86 3.85 97.00
Construction | 29 1.30 98.30
Ag/Forestry/Fisheries | 17 0.76 99.06
Entertainment/Rec Svc | 17 0.76 99.82
Mining | 4 0.18 100.00
------------------------+-----------------------------------
Total | 2,232 100.00
However, the sort option is not yet available. I shall add it to asdocx, which is almost ready. See details on asdocx here