I use the follow code to get Unique Keys with VFP tables

Local lgetUniqueKey
Use myCounter
IF Flock()
Replace myCounter.counter With myCounter.counter+1
lgetUniqueKey= myCounter.counter
Flush In myCounter Force
Unlock
Endif

Could you suggest some equivalent code if the MyCounter table is an MSSQL table?
Please no autoinc field or global unique identifiers