ALTER TABLE TableName1 ADD | ALTER [COLUMN] FieldName1
   FieldType [( nFieldWidth [, nPrecision])] [NULL | NOT NULL] [CHECK
   lExpression1 [ERROR cMessageText1]]
   [AUTOINC [NEXTVALUE NextValue [STEP StepValue]]] [DEFAULT eExpression1]
   [PRIMARY KEY | UNIQUE [COLLATE cCollateSequence]]
   [REFERENCES TableName2 [TAG TagName1]] [NOCPTRANS] [NOVALIDATE]

AUTOINC [NEXTVALUE NextValue [STEP StepValue]]
Enables automatic incrementing for the field. NextValue specifies the start value
and can be a positive or a negative integer value ranging from  2 , 147 , 483 , 647  to
- 2 , 147 , 483 , 647 . The default value is  1 . You can set NextValue using the Next
Value spin box in Fields tab of the Table Designer.
StepValue specifies the increment value for the field and can be a positive,
nonzero integer value ranging from  1  to  255 . The default value is  1 . You can set
StepValue using the Step spin box in the Fields tab of the Table Designer. 

ALTER TABLE TableName1 ALTER COLUMN FieldName1 I AUTOINC NEXTVALUE   2187