i am new to abap here i am posting my requirement can any one plese help me how to reach the requirement my requirement is to load various movements from a standard Excel sheet into ECC using custom bapi .

1. 1.      Pre-validate the input data, check GMID/Plant/storage location validation (material code is exist under plant/storage location level). Check table MARA, MARC and MARD. If not exist, return an error "GMID under plant/storage location" is invalid. 
2. 2.      Check the movement type is supportable movement type. Only the following movement type supported at this movement. Otherwise, return an error "MVT XXX is not support"

• 261/262. Goods issue to Order (CO order/ REM order) or reversal
• 301/302. Goods transfer from one plant to another plant (under same company code)
• 311. Goods transfer from Storage location to Storage location (under same plant code)
• 309. Material reclassify between two GMIDs.
• 929.Bulk TR mat.to mat
• 201/202: Goods issue to Cost center or reversal
• 901/902. Inventory taking increase/reduce
• X21/X22: GI/GR Virtual Plant Net
• 325: Transfer of storage location to storage location – blocked stock
• 343/344: Transfer of Unrestricted to Blocked/TR Blocked to Unrestricted ( TR - Transfer Return)
• 907/908: GR phys.inv.:blocked/GI phys.inv.:blocked
• 531/532: Goods receipt of by-products from order/ Reversal by-products

       3. In case of netting goods movement type X21/X22, then call AUTHORITY-CHECK to perform user have the authorization on BWART’ for            movement type’X21’ or ‘X22’ whether or not. In case of no access on that, then return an error “ You are not authorized to post transaction for                  goods movement type X21 or X22”

1. 4.      Check the batch fields (Batch 1 and Batch 2), if batch field is blank or "------------", go to system table MARA and to find the related batch. Logic as following

• First check the MARA-XCHPF, if field value is "X", go to next step. Else, keep the batch field value as blank.
• First use the material, plant code and storage location code to find the generic batch in table , if can't find, go to next step
• Use material, plant code to find the generic batch code in table . if still can't the generic batch, return an error "can't find the generic batch for plant XXXX material XXXXXXXXXXX"

1. 5.      If the value of batch field (only for source batch number GOODSMVT_ITEM-BATCH) exists, check whether the batch number exists for the source plant code (GOODSMVT_ITEM-PLANT) and material number (GOODSMVT_ITEM- MATERIAL) in the MCHA. If not exist, return an error "the batch XXX for plant XXXX & material XXXXXXXXXXX not exist in the system, please check".
2. 6.      Proposal the document date as today, and if the input goods movement posting date is empty, raise error message.
3. 7.      If the input quantity field is equal to zero, return error msg. "Input quantity of plant XXXX material XXXXXXXXXX MVT XXX is zero, please check ".
4. 8.      If the input ISO unit field is empty, return error msg. "ISO unit is missing."
5. 9.      In case any validation is failing or any error is returned from standard BAPI BAPI_GOODSMVT_CREATE, related error message should be append to the custom BAPI's return table.